Intestinal pseudo-obstruction is a rare condition in which you have symptoms of intestinal obstruction, but doctors can’t find anything blocking your intestines. In intestinal pseudo-obstruction, nerve or muscle problems slow or stop the movement of food, fluid, air, and waste through your intestines.

The intestines are part of the digestive tract and are made up of the

• small intestine, which includes the duodenum, jejunum, and ileum. Most food digestion and nutrient absorption happen in your small intestine.
• large intestine, which includes the appendix, cecum, colon, and rectum. The large intestine takes in water from stool and changes stool from a liquid to a solid form.

Intestinal pseudo-obstruction is a condition characterized by impairment of the muscle contractions that move food through the digestive tract. It can occur at any time of life, and its symptoms range from mild to severe. The condition may arise from abnormalities of the gastrointestinal muscles themselves (myogenic) or from problems with the nerves that control the muscle contractions (neurogenic).

Intestinal pseudo-obstruction leads to a buildup of partially digested food in the intestines. This buildup can cause abdominal swelling (distention) and pain, nausea, vomiting, and constipation or diarrhea. Affected individuals experience loss of appetite and impaired ability to absorb nutrients, which may lead to malnutrition. These symptoms resemble those of an intestinal blockage (obstruction), but in intestinal pseudo-obstruction no blockage is found.

Depending on the cause of intestinal pseudo-obstruction, affected individuals can have additional signs and symptoms. Some people with intestinal pseudo-obstruction have bladder dysfunction such as an inability to pass urine. Other features may include decreased muscle tone (hypotonia) or stiffness (spasticity) of the torso and limbs, weakness in the muscles that control eye movement (ophthalmoplegia), intellectual disability, seizures, unusual facial features, or recurrent infections.

When intestinal pseudo-obstruction occurs by itself, it is called primary or idiopathic intestinal pseudo-obstruction. The disorder can also develop as a complication of another health problem; in these cases, it is called secondary intestinal pseudo-obstruction. The condition can be episodic (acute) or persistent (chronic).

Intestinal pseudo-obstruction is rare, and finding out how many people have it is difficult.

In the United States, research suggests that about 100 infants are born with chronic intestinal pseudo-obstruction each year. Research conducted in Japan found that about 8 to 10 out of every 1 million people have chronic intestinal pseudo-obstruction. Experts don’t know how many teens or adults experience chronic intestinal pseudo-obstruction unrelated to symptoms in infancy, or the first year of life.

Experts think that about 100 out of every 100,000 people admitted to the hospital develop acute colonic pseudo-obstruction.

The two main types of intestinal pseudo-obstruction are chronic intestinal pseudo-obstruction and acute colonic pseudo-obstruction.

Chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction lasts a long time. This condition most often affects the small intestine or the colon, but it may affect other parts of the digestive tract, such as the stomach or esophagus.

Experts group chronic intestinal pseudo-obstruction into primary and secondary forms, depending on its cause.

Acute colonic pseudo-obstruction

Acute colonic pseudo-obstruction occurs suddenly and lasts a short time. This condition affects the colon. Other names for this condition include Ogilvie syndrome and colonic ileus.

Chronic intestinal pseudo-obstruction can occur in people of any age, but it most often occurs in children and young adults. In about 80% of cases, chronic intestinal pseudo-obstruction starts to cause symptoms in the first year of life.

Acute colonic pseudo-obstruction is more common in older adults. The condition most often occurs in people who are hospitalized for another reason, such as severe illness, injury, or surgery.

Intestinal pseudo-obstruction occurs when nerve or muscle problems slow or stop the movement of food, fluid, air, and waste through the intestines.

Chronic intestinal pseudo-obstruction

Depending on the cause, chronic intestinal pseudo-obstruction may be primary or secondary.

Primary chronic intestinal pseudo-obstruction. Experts are still studying the causes of primary chronic intestinal pseudo-obstruction and have identified different forms of this condition.

In some forms, genes cause primary chronic intestinal pseudo-obstruction, particularly when the illness begins in the first year of life. In other forms, especially when it starts in adults, the cause is unknown. When the cause is unknown, doctors may call the condition idiopathic. People with some forms of primary chronic intestinal pseudo-obstruction also have muscle or nerve problems in other parts of the digestive tract—such as the esophagus or stomach—or, less frequently, in the urinary tract.

Most of the cases in children are primary chronic intestinal pseudo-obstruction.

Secondary chronic intestinal pseudo-obstruction. Underlying health problems or other risk factors cause secondary chronic intestinal pseudo-obstruction. In adults, up to half of the cases of chronic intestinal pseudo-obstruction are secondary.

A variety of health problems may cause secondary chronic intestinal pseudo-obstruction. Examples include

• diseases and disorders that affect muscles or connective tissue, such as muscular dystrophy, lupus, and scleroderma
• diseases and disorders that affect nerves, such as Parkinson’s disease and diabetic neuropathy
• endocrine disorders, such as diabetes and hypothyroidism
• health problems that affect metabolism, such as porphyria or electrolyte imbalances
• infections, such as viral infections that also cause damage to the nerves that supply the intestines, including herpes and Epstein-Barr virus
• other health problems, including celiac disease, Crohn’s disease, and some types of cancer

Other causes of secondary chronic intestinal pseudo-obstruction include

• medicines, such as opiates and antidepressants
• radiation therapy to treat cancer
• toxins—poisonous substances

Acute colonic pseudo-obstruction

Acute colonic pseudo-obstruction most often occurs in people who have a severe illness or injury or those who recently had surgery.

Health problems that may lead to acute colonic pseudo-obstruction include

• diseases and disorders that affect nerves, such as Parkinson’s disease
• heart attack, heart failure, and stroke
• infection and sepsis
• injury or physical trauma, including hip or back injury
• problems that affect metabolism, such as kidney failure, liver failure, and electrolyte imbalances
• some types of cancer, especially when cancer spreads to the area where the nerves from the spine connect with the intestines

Other factors linked to acute colonic pseudo-obstruction include

• medicines, such as opiates and antidepressants
• pregnancy, vaginal delivery, or Cesarian section
• radiation therapy to treat cancer
• surgery, such as abdominal surgery, heart surgery, organ transplantation, and joint replacement, especially knee and hip replacement

In some individuals with primary intestinal pseudo-obstruction, the condition is caused by genetic changes affecting the FLNA or ACTG2 gene.

The protein produced from the FLNA gene, filamin A, attaches (binds) to proteins called actins and helps them form the branching network of filaments that make up the cytoskeleton, which gives structure to cells and allows them to change shape and move. FLNA gene mutations that cause intestinal pseudo-obstruction are thought to reduce levels of the filamin A protein or impair its function. Research suggests that decreased filamin A function may affect the shape of cells in the smooth muscles of the gastrointestinal tract during development before birth, causing abnormalities in the layering of these muscles. Smooth muscles line the internal organs; they contract and relax without being consciously controlled. In the gastrointestinal tract, abnormal layering of these muscles interferes with the ability to produce the coordinated waves of contractions (peristalsis) that move food along during digestion.

Deletions or duplications of genetic material can affect all or part of the FLNA gene, and may also include adjacent genes on the X chromosome. Changes in adjacent genes may account for some of the other signs and symptoms that can occur with intestinal pseudo-obstruction.

The ACTG2 gene provides instructions for making a member of the actin family called gamma (γ)-2 actin. The γ-2 actin protein is found in smooth muscle cells of the intestinal and urinary tracts. It is necessary for contraction of the smooth muscles in the intestines and bladder. These contractions move food through the intestines as part of the digestive process and empty urine from the bladder. ACTG2 gene mutations hinder the formation of actin filaments in the cytoskeleton and reduce the ability of smooth muscles in the intestines and bladder to contract, leading to the signs and symptoms of intestinal pseudo-obstruction.

Secondary intestinal pseudo-obstruction occurs as a complication of other disorders that damage muscles or nerves in the intestinal tract, such as Parkinson's disease, type 2 diabetes, various types of muscular dystrophy, or Kawasaki disease. Additionally, the condition is a characteristic feature of certain inherited syndromes such as megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) or mitochondrial neurogastrointestinal encephalopathy disease (MNGIE disease). Infections, surgery, or certain drugs can also cause secondary intestinal pseudo-obstruction.

Mutations in other genes involved in smooth muscle contraction can also cause intestinal pseudo-obstruction. Studies suggest that mutations in additional genes that have not been identified can also result in this condition. In some affected individuals, the cause of intestinal pseudo-obstruction is unknown.

Normal Function

The ACTG2 gene provides instructions for making a protein called gamma (γ)-2 actin, which is part of the actin protein family. Actin proteins are organized into filaments, which are important for the tensing of muscle fibers (muscle contraction) and cell movement. These filaments also help maintain the cytoskeleton, which is the structural framework that determines cell shape and organizes cell contents.

The γ-2 actin protein is found in smooth muscle cells of the urinary and intestinal tracts. Smooth muscles line the internal organs; they contract and relax without being consciously controlled. The γ-2 actin protein is necessary for contraction of the smooth muscles in the bladder and intestines. These contractions empty urine from the bladder and move food through the intestines as part of the digestive process.

Health Conditions Related to Genetic Changes

Intestinal pseudo-obstruction

Several inherited mutations in the ACTG2 gene have been identified in people with intestinal pseudo-obstruction, a condition that impairs the smooth muscle contractions that move food through the digestive tract (peristalsis). This condition mimics a physical blockage of the intestines without an actual obstruction. Problems with emptying the bladder can also occur in people with this disorder.

The ACTG2 gene mutations that cause intestinal pseudo-obstruction are thought to hinder the formation of actin filaments in the cytoskeleton and reduce the ability of smooth muscles in the intestines and bladder to contract. As a result, peristalsis in the intestines is impaired and the bladder is less able to contract and expel urine, leading to the signs and symptoms of this condition.

Megacystis-microcolon-intestinal hypoperistalsis syndrome

At least 22 ACTG2 gene mutations have been found to cause megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), which is characterized by impairment of peristalsis and emptying the bladder.

The ACTG2 gene mutations that cause MMIHS are not inherited; rather they occur as a random (de novo) event during the formation of reproductive cells (eggs or sperm) or in early embryonic development. The alterations change single protein building blocks (amino acids) in the γ-2 actin protein. These changes hinder the formation of actin filaments and reduce the ability of smooth muscles in the bladder and intestines to contract. As a result, the bladder cannot empty normally, leading to an enlarged bladder (megacystis) and painful abdominal swelling (distention). In addition, partially digested food can build up in the intestines, which also contributes to distention. Poor digestion may lead to malnutrition in people with MMIHS.

Other disorders

ACTG2 gene mutations cause a spectrum of disorders (sometimes referred to as ACTG2-related disorders), with MMIHS (described above) at the severe end. As in MMIHS, most of these mutations change single amino acids in the γ-2 actin protein. However, in less severely affected individuals, the mutations are usually inherited. These mutations often cause intestinal pseudo-obstruction (described above). In some affected individuals, the smooth muscle problems are episodic and come and go throughout life. Intestinal malrotation can also occur in people with ACTG2 gene mutations. This condition occurs when the intestines do not fold properly; instead, they twist abnormally, which can impede the movement of food. Effects on the urinary tract include recurrent urinary tract infections and impaired bladder function. Individuals with inherited ACTG2 gene mutations can have one or more of these intestinal or urinary tract abnormalities; they are usually milder than MMIHS, or they begin later in life. It is unclear why inherited and de novo mutations result in conditions with different severities.

Other Names for This Gene

• ACT
• ACTA3
• ACTE
• actin, gamma-enteric smooth muscle isoform 1 precursor
• actin, gamma-enteric smooth muscle isoform 2 precursor
• actin-like protein
• ACTL3
• ACTSG
• alpha-actin-3
• VSCM

Genomic Location

Normal Function

The FLNA gene provides instructions for producing the protein filamin A, which helps build cells' extensive internal network of protein filaments called the cytoskeleton. The cytoskeleton gives structure to cells and allows them the flexibility to change shape. The cytoskeleton is also important for certain processes inside the cells, such as the movement of proteins within the cell and the breakdown of unneeded proteins. Filamin A primarily attaches (binds) to another protein called actin and helps it form the branching network of filaments that make up the cytoskeleton.

Filamin A can also bind to many other proteins in the cell to carry out various functions, including the attachment of cells to one another (cell adhesion), cell movement (migration), determination of cell shape, the relay of signals within cells, and cell survival. These numerous functions involving filamin A have been found to play roles in regulating skeletal and brain development, the formation of heart tissue and blood vessels, blood clotting, skin elasticity, the maintenance of lung tissue, and the function of the digestive system.

Filamin A is also involved in the organization of the extracellular matrix, which is the lattice of proteins and other molecules outside the cell. Filamin A binds to proteins called integrins, which span the cell membrane and anchor cells to the extracellular matrix. Through this binding, cells are correctly positioned and signals can be exchanged between the cell and the extracellular matrix.

Health Conditions Related to Genetic Changes

Frontometaphyseal dysplasia

Variants (also known as mutations) in the FLNA gene have been identified in people with frontometaphyseal dysplasia. This condition is a member of a group of related conditions called otopalatodigital spectrum disorders, which also includes otopalatodigital syndrome type 1, otopalatodigital syndrome type 2, frontometaphyseal dysplasia, and Melnick-Needles syndrome (described below). Frontometaphyseal dysplasia involves abnormalities in skeletal development, particularly involving the joints, and other health problems, including kidney, heart, and airway defects.

FLNA gene variants that cause frontometaphyseal dysplasia are described as "gain of function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Different variants in the FLNA gene appear to produce specific changes in the protein, resulting in particular signs and symptoms that are classified as individual FLNA-related disorders. Researchers suspect that the variants involved in frontometaphyseal dysplasia may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of the condition.

Intestinal pseudo-obstruction

Several variants in the FLNA gene have been identified in people with intestinal pseudo-obstruction, a condition characterized by impairment of the muscle contractions that move food through the digestive tract (peristalsis).

The FLNA gene variants that cause intestinal pseudo-obstruction include deletions or duplications of genetic material. The variants are thought to reduce levels of the filamin A protein or impair its function; this type of variant is called "loss of function." Research suggests that decreased filamin A function may affect the shape of cells in the smooth muscles of the gastrointestinal tract during development before birth, causing abnormalities in the layering of these muscles. Smooth muscles line the internal organs; they contract and relax without being consciously controlled. Abnormal layering of these muscles may interfere with these musclar movements that move food through the digestive tract.

Deletions or duplications of genetic material can affect all or part of the FLNA gene, and may also include nearby genes on the X chromosome. Changes in these additional genes may account for some of the other signs and symptoms, such as neurological abnormalities and unusual facial features, that occur in some affected individuals.

Melnick-Needles syndrome

Several variants in a region of the FLNA gene called exon 22 have been identified in people with Melnick-Needles syndrome. This condition is typically the most severe of the otopalatodigital spectrum disorders (described above). It involves abnormalities in skeletal development, causing short stature, abnormal curvature of the spine, partial dislocation of joints, and other health problems. The FLNA gene variants associated with Melnick-Needles syndrome are described as "gain of function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Researchers believe that the variants involved in Melnick-Needles syndrome may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of the condition.

Otopalatodigital syndrome type 1

Several variants in the FLNA gene have been found to cause otopalatodigital syndrome type 1. This condition is typically the mildest of the otopalatodigital spectrum disorders (described above). It is characterized by hearing loss caused by malformations in tiny bones in the ears (ossicles), an opening in the roof of the mouth (cleft palate), and skeletal abnormalities involving the fingers or toes (digits).

The FLNA gene variants that cause otopalatodigital syndrome type 1 all result in changes to the filamin A protein in a region that binds to actin (known as the CH2 domain). Many of these variants change single amino acids in the filamin A protein. These variants are described as "gain-of-function" because they appear to lead to a protein with an increased ability to bind to actin. Researchers believe that the FLNA gene variants impair the stability of the cytoskeleton and disrupt cellular processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of otopalatodigital syndrome type 1.

Otopalatodigital syndrome type 2

Several variants in the FLNA gene have been found to cause otopalatodigital syndrome type 2, which is part of the otopalatodigital spectrum (described above). This condition is similar to otopalatodigital syndrome type 1 (described above) and is characterized by hearing loss caused by malformations in the ossicles, a cleft palate, and skeletal abnormalities involving the digits. These abnormalities in skeletal development are typically more severe than in otopalatodigital syndrome type 1.

The FLNA gene variants that cause otopalatodigital syndrome type 2 all result in changes to the filamin A protein in a region that binds to actin (known as the CH2 domain). Most of these variants change single amino acids in the filamin A protein. These variants are described as "gain-of-function" because they appear to lead to a protein with an increased ability to bind to actin. Researchers believe that the FLNA gene variants impair the stability of the cytoskeleton and disrupt cellular processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of otopalatodigital syndrome type 2.

Periventricular heterotopia

Hundreds of FLNA gene variants have been identified in individuals with periventricular heterotopia, a condition in which nerve cells (neurons) do not move (migrate) properly during the early development of the fetal brain leading to seizures and other neurological problems. Most of these variants result in a lack of filamin A protein, which makes the cytoskeleton disorganized and impairs the attachment (adhesion) of cells to one another. Impaired adhesion alters cells that line the fluid-filled cavities near the center of the brain (the ventricles), which is where neurons develop. Disruption of this lining prevents the movement of neurons to the surface of the brain. Neurons that do not migrate properly during development form clumps (nodules) around the ventricles, resulting in the signs and symptoms of periventricular heterotopia.

In some cases, variants result in the substitution of one protein building block (amino acid) for another amino acid in the protein sequence. These variants may result in the production of a partially functional protein, sometimes causing a milder form of the disorder.

Terminal osseous dysplasia

At least one variant in the FLNA gene has been found to cause terminal osseous dysplasia, which is part of the otopalatodigital spectrum of disorders (described above). Terminal osseous dysplasia is characterized by skeletal abnormalities in the hands and feet, noncancerous (benign) tumors on the fingers and toes (digits), and dark patches of skin on the face.

The FLNA gene variant that causes terminal osseous dysplasia changes a single DNA building block (nucleotide) in the gene, substituting adenine for guanine at DNA position 5217 (written as 5217G>A). This DNA change alters the way the blueprint for making the filamin A protein is put together. The version of the protein made using this blueprint is abnormally short. Researchers suspect the altered protein may not be able to interact with other molecules normally. It is thought that the inability to bind to other proteins disrupts important processes involved in skeletal development and cell growth, leading to the bone and skin abnormalities characteristic of terminal osseous dysplasia.

X-linked cardiac valvular dysplasia

Variants in the FLNA gene have been found to cause X-linked cardiac valvular dysplasia, a condition characterized by abnormally thick heart valves. Most of these variants change single amino acids in the filamin A protein. These variants likely alter the shape of the protein, impairing its ability to bind to actin and other proteins. As a result, the cell cytoskeleton is weakened and valve cells and the extracellular matrix are disorganized. The cells are not positioned properly within the valve, so the valve becomes malformed. In addition, the cells' decreased ability to change shape impairs the valves' ability to open and close when the heart pumps blood. It appears that excess proteins are produced in the abnormal extracellular matrix, causing the valves to become thickened and further impairing their ability to open and close normally.

It is unclear why the heart valves are the only tissue affected by these FLNA gene variants. The variants that cause X-linked cardiac valvular dysplasia occur in a different part of the gene than those that cause other disorders (described above). It has been suggested that the region of the filamin A protein affected by these variants is necessary for binding to other proteins that play a significant role in heart development.

FG syndrome

MedlinePlus Genetics provides information about FG syndrome

Other Names for This Gene

• ABP-280
• ABPX
• actin-binding protein 280
• DKFZp434P031
• filamin 1
• filamin A, alpha
• filamin A, alpha (actin binding protein 280)
• FLN
• FLN1
• FLNA_HUMAN

Genomic Location

Normal Function

The MYH11 gene provides instructions for making a protein called smooth muscle myosin heavy chain 11. It belongs to a group of proteins called myosins, which are involved in cell movement and the transport of materials within and between cells. Thick filaments made of myosin, along with thin filaments of another protein called actin, are the primary components of muscle fibers and are important for muscle tensing (contraction). Smooth muscle myosin heavy chain 11 forms part of a myosin protein complex found in smooth muscles. Smooth muscles are the muscles that line the internal organs of the body, including the blood vessels, stomach, and intestines; as part of their normal function in the body, these muscles contract and relax involuntarily.

Each myosin protein complex consists of two pairs of light chains, which regulate the complex and are produced from several other genes, and two heavy chains such as that produced from the MYH11 gene. The heavy chains each have two parts: a head region and a tail region. The head region interacts with actin and includes a segment that attaches (binds) to ATP. ATP is a molecule that supplies energy for the cells' activities, including muscle contraction. The long tail region of the myosin heavy chain interacts with other proteins, including the tail regions of other myosins, enabling them to form thick filaments.

Health Conditions Related to Genetic Changes

Core binding factor acute myeloid leukemia

Rearrangements of genetic material involving the MYH11 gene are involved in a form of blood cancer known as acute myeloid leukemia (AML). The most common of these rearrangements is an inversion of a region of chromosome 16 (written as inv(16)). An inversion involves breakage of the chromosome in two places; the resulting piece of DNA is reversed and reinserted into the chromosome. Less commonly, a rearrangement known as a translocation occurs between the two copies of chromosome 16 (written as t(16;16)). In this translocation, pieces of DNA from each copy of the chromosome break off and are interchanged. Both types of genetic rearrangement result in the fusion of two genes found on chromosome 16, CBFB and MYH11. These rearrangements are associated with 5 to 8 percent of AML cases in adults. AML associated with either inv(16) or t(16;16) is classified as core binding factor AML (CBF-AML).

The protein produced from the normal CBFB gene interacts with another protein called RUNX1 to form a complex called core binding factor (CBF). This complex attaches to specific areas of DNA and turns on genes that are involved in the development of blood cells. The protein produced from the fusion gene, CBFβ-MYH11, can still bind to RUNX1; however, the function of CBF is impaired. The presence of CBFβ-MYH11 may block binding of CBF to DNA, impairing its ability to control gene activity. Alternatively, the MYH11 portion of the fusion protein may interact with other proteins that prevent the complex from controlling gene activity. This change in gene activity blocks the maturation (differentiation) of blood cells and leads to the production of abnormal, immature white blood cells called myeloid blasts. While inv(16) and t(16;16) are important for leukemia development, one or more additional genetic changes are typically needed for the myeloid blasts to develop into cancerous leukemia cells.

Familial thoracic aortic aneurysm and dissection

MedlinePlus Genetics provides information about Familial thoracic aortic aneurysm and dissection

Intestinal pseudo-obstruction

MedlinePlus Genetics provides information about Intestinal pseudo-obstruction

Megacystis-microcolon-intestinal hypoperistalsis syndrome

MedlinePlus Genetics provides information about Megacystis-microcolon-intestinal hypoperistalsis syndrome

Other Names for This Gene

• AAT4
• FAA4
• MYH11_HUMAN
• myosin heavy chain, smooth muscle isoform
• myosin, heavy chain 11, smooth muscle
• myosin, heavy polypeptide 11, smooth muscle
• myosin-11
• myosin-11 isoform SM1A
• myosin-11 isoform SM1B
• myosin-11 isoform SM2A
• myosin-11 isoform SM2B
• SMHC
• SMMHC

Genomic Location

Intestinal pseudo-obstruction is often not inherited, and most affected individuals do not have a family history of the disorder. When it does run in families, it can have different inheritance patterns.

Intestinal pseudo-obstruction caused by FLNA gene mutations is inherited in an X-linked recessive pattern. The FLNA gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

Intestinal pseudo-obstruction caused by ACTG2 gene mutations is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Some other cases of intestinal pseudo-obstruction are inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Symptoms of intestinal pseudo-obstruction vary from person to person. Symptoms may include

• abdominal pain
• bloating and feeling too full after eating a meal
• nausea and vomiting 
• constipation
• diarrhea

Chronic intestinal pseudo-obstruction often causes symptoms after meals. Symptoms may be long-lasting or may come and go over time. Symptoms may be more severe at times, called acute episodes, and milder between these episodes. If chronic intestinal pseudo-obstruction affects parts of the digestive tract outside the intestines, it may cause additional symptoms. For example, if the condition affects the esophagus, it may cause problems with swallowing.

Acute colonic pseudo-obstruction symptoms may include the inability to pass stool or gas, along with the symptoms listed above. Symptoms may occur even when you don’t eat or drink.

If you or your child have symptoms of intestinal pseudo-obstruction, you should see a doctor or take your child to see a doctor right away, especially if the symptoms are severe or don’t go away. These symptoms could be a sign of either intestinal obstruction—a blockage in the intestines—or pseudo-obstruction. Without treatment, intestinal obstruction and pseudo-obstruction may lead to life-threatening complications.

Chronic intestinal pseudo-obstruction and acute colonic pseudo-obstruction may lead to different complications.

Chronic intestinal pseudo-obstruction

Over time, chronic intestinal pseudo-obstruction may lead to

• malnutrition and weight loss.
• small intestinal bacterial overgrowth, an increase in the number of bacteria or a change in the type of bacteria in the small intestine. This bacterial overgrowth can affect the small intestine’s ability to absorb nutrients, including fat and fat-soluble vitamins A, D, E, and K.
• intestinal failure, which means the small intestine can’t absorb enough nutrients and water to maintain health or support growth.

Acute colonic pseudo-obstruction

Acute colonic pseudo-obstruction may cause severe swelling of the colon, which can lead to complications such as

• lack of blood flow to part of the colon.
• a perforation, or hole, in the wall of the colon. A perforation can allow the contents of the colon to spill into the abdominal cavity, which may lead to peritonitis—an infection of the lining of the abdominal cavity. Peritonitis may sometimes spread to the bloodstream, which can be life threatening.

To diagnose intestinal pseudo-obstruction, the doctor will ask about symptoms, review medical and family history, perform a physical exam, and order tests.

Physical exam

During a physical exam, the doctor may

• check for bloating in the abdomen
• use a stethoscope to listen to sounds inside the abdomen
• press on the abdomen to feel for tenderness or masses
• check for signs of complications, such as fever or a fast heart rate

Doctors may order medical tests to rule out an intestinal obstruction—a physical blockage in the intestines—and to diagnose intestinal pseudo-obstruction. Doctors may also order tests to check for causes of intestinal pseudo-obstruction.

Doctors may order different tests, depending on which type of pseudo-obstruction they think a person has.

• To diagnose chronic intestinal pseudo-obstruction, doctors may order blood tests, imaging tests such as computed tomography (CT) scans, endoscopy tests, biopsies, and other tests.
• To diagnose acute colonic pseudo-obstruction, doctors most often order blood tests and imaging tests, such as x-rays of the abdomen or CT scans.

Blood tests

For a blood test, a health care professional will take a blood sample and send the sample to a lab. Doctors may order blood tests to help find the cause of pseudo-obstruction or to check for complications.

Imaging tests

Doctors may order imaging tests, including

• x-rays, which use a small amount of radiation to create pictures of the inside of the body
• CT scans, which use a combination of x-rays and computer technology to create images
• magnetic resonance imaging (MRI), which takes pictures of the body’s internal organs and soft tissues without using x-rays
• upper GI series, which uses x-rays and water-soluble contrast medium—a special liquid that makes the digestive tract easier to see on x-rays—to view the upper GI tract, including the small intestine
• lower GI series, which uses x-rays and water-soluble contrast medium to view the lower GI tract

Endoscopy tests

Doctors may order endoscopy tests to help diagnose chronic intestinal pseudo-obstruction. During an endoscopy, doctors use an endoscope—a long, flexible, narrow tube with a light and tiny camera on one end—to view inside the digestive tract. Two types of endoscopy tests are

• upper GI endoscopy, which doctors use to see inside the upper GI tract
• colonoscopy, which doctors use to see inside the lower GI tract

Doctors may take biopsies during endoscopy tests.

Biopsies

To help diagnose chronic intestinal pseudo-obstruction, doctors may take biopsies—small pieces of tissue—from the digestive tract lining or intestinal wall.

A doctor may take biopsies during an endoscopy test by passing an instrument through the endoscope to take a small piece of tissue. In some cases, doctors may perform surgery to take biopsies of the intestinal wall. If a patient is having surgery to treat chronic intestinal pseudo-obstruction, doctors may take biopsies during the surgery. Biopsies of the intestinal wall may help doctors find the cause of chronic intestinal pseudo-obstruction.

A pathologist will examine the biopsy tissue under a microscope to check for signs of chronic intestinal pseudo-obstruction or health problems that could cause pseudo-obstruction.

Other tests

Doctors may order additional tests to find out how well the digestive tract is working. These tests can help diagnose chronic intestinal pseudo-obstruction, find the cause, or guide treatment. Examples include

• scintigraphy tests. These tests involve eating a meal with a small dose of a radioactive substance. Doctors use special computers and external cameras to track the substance as it passes through the digestive tract.
• manometry tests. These tests measure muscle pressure and movements in part of the digestive tract, such as the esophagus, small intestine, colon, or rectum and anus.
• gastric emptying breath test. This test involves eating a meal that contains a substance that is absorbed in the intestines and is eventually passed into the breath. After a person eats the meal, a health care professional collects samples of his or her breath over a period of a few hours. The test can show how fast the stomach empties by measuring the amount of the substance in the breath.

Doctors recommend different treatments for chronic intestinal pseudo-obstruction and acute colonic pseudo-obstruction.

Chronic intestinal pseudo-obstruction

Doctors treat chronic intestinal pseudo-obstruction with nutrition support, medicines, decompression, and sometimes surgery. If an underlying health problem is causing chronic intestinal pseudo-obstruction, doctors will also treat the underlying health problem as needed.

Nutrition support. People with chronic intestinal pseudo-obstruction may have problems getting enough nutrients from their food and drinks. Doctors may recommend diet changes to help prevent malnutrition and weight loss. Doctors often recommend a diet low in fat and uncooked fiber.

However, people who can’t get enough nutrients from their diet may need nutrition support. Nutrition support may include

• enteral nutrition, in which a person receives liquid food through a tube inserted into the stomach or small intestine. The tube may be inserted through the nose, or it may be inserted through the wall of the abdomen during surgery or with the help of endoscopy.
• parenteral nutrition, in which a person receives nutrients through an intravenous (IV) tube, which is a tube inserted into a vein.

Parenteral nutrition may lead to serious complications, such as blood clots in veins or infections. Doctors only recommend parenteral nutrition if a person can’t get enough nutrients from their diet or from enteral nutrition.

Medicines. Doctors may prescribe medicines to help relieve the symptoms of chronic intestinal pseudo-obstruction, including

• medicines that help food move through the digestive tract more quickly.
• medicines that help relieve nausea and vomiting.
• antibiotics, which doctors may prescribe to treat small intestinal bacterial overgrowth.
• pain medicines, if needed. Doctors may recommend avoiding pain medicines, such as opioids, that slow down food moving through the digestive tract and may worsen the pseudo-obstruction.

Decompression. Decompression means removing gas and fluids from the digestive tract to relieve pressure and symptoms of pseudo-obstruction. To decompress the digestive tract, doctors may

• insert a tube through the nose and into the stomach
• perform a colonoscopy
• perform surgery

Surgery. In some cases, doctors recommend surgery to treat chronic intestinal pseudo-obstruction. Types of surgery include

• gastrostomy or jejunostomy, in which doctors place a tube from outside your body through the abdominal wall, directly into the stomach or small intestine. The tube can be used for enteral nutrition and for decompression.
• ileostomy or colostomy, which may help with decompression.
• bowel resection, or surgery to remove part of the intestine, which doctors recommend rarely, usually when imaging tests show the pseudo-obstruction affects only a segment of the intestine.
• intestinal transplant, which doctors may recommend for people who require parenteral nutrition but cannot start or continue parenteral nutrition safely.

Acute colonic pseudo-obstruction

Doctors most often treat acute colonic pseudo-obstruction with an approach called conservative management. In some cases, other treatments may be needed.

Conservative management. Doctors may treat acute colonic pseudo-obstruction with conservative management if you are not likely to have or develop complications. As part of conservative management, doctors typically

• stop any medicines that could worsen the pseudo-obstruction, especially opioid pain medicines
• treat any infections or other health problems
• instruct you not to eat or drink anything because pseudo-obstruction will stop the movement of food, fluid, air, and waste through your intestines
• give you IV fluid and electrolytes as needed
• give you medicine to help relieve the pseudo-obstruction
• insert tubes into your stomach or rectum to decompress your digestive tract
• encourage you to walk if you can

Other treatments. If acute pseudo-obstruction doesn’t improve with conservative management in 2 or 3 days, doctors may recommend other treatments. Doctors may also recommend other treatments if you have, or are likely to develop, complications. Other treatments may include

• medicine to help relieve the pseudo-obstruction.
• a colonoscopy to decompress the colon. In some cases, during colonoscopy, doctors place a tube in the colon and leave it there for a few days to help with decompression. The tube will eventually pass naturally.
• surgery to decompress the colon or to remove part of the colon damaged by complications, particularly perforation.

Doctors may recommend diet changes for people who have intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction

For people who have chronic intestinal pseudo-obstruction, diet changes may help reduce symptoms and prevent complications, such as malnutrition, weight loss, and small intestinal bacterial overgrowth.

Doctors may recommend

• a diet low in fat, fiber, lactose, and fructose
• cooking all vegetables and passing them through a blender to make them easier to digest
• eating five or six small meals per day
• liquid meals and dietary supplements
• vitamin supplements

For safety reasons, talk with your doctor before using dietary supplements or any other complementary or alternative medicines or practices.

People who aren’t able to get enough nutrients from their diet may need nutrition support. Nutrition support may include enteral nutrition or parenteral nutrition.

Acute colonic pseudo-obstruction

As part of conservative management for acute colonic pseudo-obstruction, your doctor may instruct you not to eat or drink anything for a short time. Health care professionals will give you intravenous (IV) fluids and electrolytes as needed.