Dumping syndrome is a group of symptoms, such as diarrhea, nausea, or feeling light-headed or tired after a meal, that are caused by rapid gastric emptying. Rapid gastric emptying is a condition in which food moves too quickly from your stomach to your duodenum.

About 1 in 10 people who have stomach surgery develop dumping syndrome. Dumping syndrome is more common after some types of surgery than others.

For example, dumping syndrome is more common after gastric bypass bariatric surgery than after other types of bariatric surgery. Dumping syndrome is also more common after a gastrectomy that removes the entire stomach than after a gastrectomy that removes only part of the stomach.

Early dumping syndrome is more common than late dumping syndrome. Some people have both forms. Among people with dumping syndrome, about 1 in 4 have late dumping syndrome alone.

Dumping syndrome has two forms

• early dumping syndrome, in which you have symptoms within 30 minutes after eating a meal
• late dumping syndrome, in which you have symptoms 1 to 3 hours after eating a meal

Early and late dumping syndromes have different symptoms.

Dumping syndrome most often occurs in people who’ve had surgery of the stomach or esophagus.

Rapid gastric emptying, a condition in which food moves too quickly from your stomach to your duodenum, causes dumping syndrome.

Your digestive tract makes and releases hormones that control how your digestive system works. When food moves too quickly from your stomach to your duodenum, your digestive tract releases more hormones than normal. Fluid also moves from your blood stream into your small intestine. Experts think that the excess hormones and movement of fluid into your small intestine cause the symptoms of early dumping syndrome.

Experts also think that these excess hormones may cause your pancreas to produce too much insulin. Too much insulin can lead to low blood glucose 1 to 3 hours after a meal, causing the symptoms of late dumping syndrome.

Causes of rapid gastric emptying

The most common cause of rapid gastric emptying and dumping syndrome is surgery of the stomach or esophagus. Types of surgery that may lead to dumping syndrome include

• bariatric surgery, such as gastric bypass surgery and gastric sleeve surgery. These operations help people lose weight.
• esophagectomy, which is surgery to remove part of the esophagus. Doctors use this surgery to treat problems of the esophagus, such as esophageal cancer and Barrett’s esophagus.
• fundoplication, which is surgery to sew the top of the stomach around the esophagus. Doctors use this surgery to treat gastroesophageal reflux disease and hiatal hernia.
• gastrectomy, which is surgery to remove all or part of the stomach. Doctors use this surgery to treat stomach cancer and peptic ulcers.
• vagotomy, which is surgery to cut the vagus nerve in the stomach so that the stomach makes less acid. Doctors use this surgery to treat peptic ulcers.

Rapid gastric emptying sometimes occurs in people who have not had stomach surgery. For example, rapid gastric emptying may occur in people who have

• recently developed diabetes, especially type 2 diabetes
• pancreatic exocrine insufficiency, a condition in which the pancreas doesn’t make enough of certain enzymes, causing problems with digestion
• duodenal ulcers
• Zollinger-Ellison syndrome

In some cases, a person has rapid gastric emptying and dumping syndrome but the cause is unknown.

The symptoms of early and late dumping syndrome are different. Symptoms may vary from person to person.

Early dumping syndrome

Symptoms of early dumping syndrome occur within 30 minutes after you eat a meal. You may have digestive symptoms, such as

• diarrhea
• feeling uncomfortably full or bloated
• nausea
• pain and cramping in your abdomen
• stomach “growling” or rumbling sounds

Other symptoms of early dumping syndrome may include

• feeling light-headed or fainting
• feeling tired or needing to lie down
• flushing, or reddening of your face, neck, or upper chest
• having a fast or irregular heartbeat
• headache
• sweating

Late dumping syndrome

Symptoms of late dumping syndrome occur 1 to 3 hours after you eat a meal. The symptoms of late dumping syndrome are caused by low blood glucose, also called low blood sugar or hypoglycemia. Symptoms of late dumping syndrome may include

• feeling light-headed or fainting
• feeling shaky or jittery
• feeling tired
• having a fast or irregular heartbeat
• trouble concentrating
• sweating
• weakness

Some people with severe dumping syndrome may avoid eating to prevent symptoms. This can lead to weight loss and malnutrition.

Avoiding eating to prevent symptoms canlead to weight loss and malnutrition.

To diagnose dumping syndrome, your doctor will review your medical history and symptoms and may order tests to confirm the diagnosis.

Medical history

Your doctor will review your medical history, including any history of stomach or esophagus surgery.

Review of your symptoms

Doctors typically diagnose dumping syndrome based on symptoms. Doctors may use a scoring system that assigns point values to different symptoms or may ask you to complete a special questionnaire. Scoring systems and questionnaires can help your doctor find out if you most likely have dumping syndrome or a different health problem.

Doctors typically diagnose dumping syndrome based on symptoms.

Doctors may use the following tests to confirm that you have dumping syndrome and rule out other conditions with similar symptoms.

Oral glucose tolerance test

You’ll be asked to fast—not eat or drink anything except water—for at least 10 hours before the test. For the test, you’ll drink a solution that contains glucose, a form of sugar. A health care professional will take blood samples and check your blood pressure and heart rate before you drink the glucose solution and then every 30 minutes for up to 3 hours.

The health care professional will use blood samples to measure your blood glucose level, also called blood sugar, and your hematocrit. A hematocrit test measures how much of your blood is made up of red blood cells. When you have dumping syndrome, fluid moves from your blood stream into your small intestine after a meal. With less fluid in your blood, the portion of your blood made up of red blood cells increases.

Your doctor may diagnose dumping syndrome if

• your heart rate increases by 10 beats per minute 30 minutes after you drink the glucose solution
• your blood test results show a 3 percent increase in your hematocrit 30 minutes after you drink the glucose solution
• your blood test results show low blood glucose 1 to 3 hours after you drink the glucose solution

Gastric emptying scan

A gastric emptying scan is also called gastric emptying scintigraphy. For this test, you eat a bland meal—such as eggs or an egg substitute—that contains a small amount of radioactive material. A camera outside your body scans your abdomen to show where the radioactive material is located. By tracking the radioactive material, a health care professional can measure how fast your stomach empties after the meal. The health care professional will scan your abdomen several times to see how fast your stomach empties for up to 4 hours after the meal. The test can help confirm a diagnosis of dumping syndrome.

Other tests

Your doctor may order additional tests, such as upper gastrointestinal (GI) endoscopy or upper GI series, to examine the structure of your esophagus, stomach, and small intestine and to check for signs of other health problems.

Experts have not found a way for people to prevent dumping syndrome. If you have dumping syndrome, you may be able to prevent future symptoms with treatments such as changing your eating habits.

Doctors treat dumping syndrome by recommending changes to how and what you eat, medicines, and, in some cases, surgery.

Changing your eating habits

The first step in treating dumping syndrome is changing how and what you eat. Many people with dumping syndrome have mild symptoms that improve over time with simple changes in eating and diet.

Medicines

If changing your eating habits doesn’t improve your symptoms, you doctor may prescribe medicines.

Octreotide (Sandostatin) may help reduce the symptoms of dumping syndrome. This medicine comes in short- and long-acting forms

• The short-acting form is injected under your skin 2 to 4 times a day before meals. A health care professional may inject the medicine or may train you, a friend, or a relative to inject the medicine.
• The long-acting form is injected into your buttocks muscles once every 4 weeks. Side effects may include pain where the medicine is injected, diarrhea, weight gain, gallstones, and steatorrhea.

Doctors may prescribe acarbose (Prandase, Precose) to help reduce the symptoms of late dumping syndrome. Side effects of acarbose may include bloating, diarrhea, and flatulence.

Surgery

If stomach or esophagus surgery caused your dumping syndrome and other treatments don’t improve your symptoms enough, your doctor may recommend another surgery to try to correct dumping syndrome. The type of surgery your doctor recommends depends on the type of surgery that led to your dumping syndrome. Surgery to correct dumping syndrome doesn’t always work.

The first step in treating dumping syndrome is changing how and what you eat. Many people with dumping syndrome have mild symptoms that improve over time with simple changes in eating and diet.

Changing how you eat

Your doctor may recommend

• eating six small meals a day, instead of three larger meals
• waiting to drink liquids until at least 30 minutes after a meal
• lying down for 30 minutes after you eat a meal

Your doctor may recommend eating six small meals a day, instead of three larger meals.

Changing what you eat

Your doctor may recommend

• eating more protein, fiber, and fat
• eating less carbohydrates and choosing foods that contain complex carbohydrates—such as whole grains, fruits, and vegetables—rather than foods that contain simple sugars—such as candies, cookies, sugary drinks, and other foods and drinks that have added sugar
• avoiding milk and milk products
• adding pectin or guar gum—plant extracts used as thickening agents—to your food