Dieulafoy lesion is an abnormally large artery (a vessel that takes blood from the heart to other areas of the body) in the lining of the gastrointestinal system. It is most common in the stomach but can occur in other locations, including the small and large intestine. Dieulafoy lesions can cause severe and sudden gastrointestinal bleeding. The condition occurs in people of all ages, but is more common in males than in females. Depending upon the site of the bleeding, symptoms may include vomiting up blood (hematemesis); sticky, dark-colored stools (melena); passage of fresh blood in the stool (hematochezia); or coughing up blood (hemoptysis). Some affected individuals may only present with blood pressure problems. Treatment may include endoscopic and/or surgical techniques. Though treatment can be effective, Dieulafoy lesions and the associated blood loss can be fatal, especially if not diagnosed and treated promptly.

Dieulafoy lesions may not cause symptoms until the lining of the stomach or intestine wears away, exposing the artery. The cause of Dieulafoy lesions is not well-understood. Some believe the lesions are congenital (present at birth), while others believe they occur later in life. In some cases, Dieulafoy lesions have been associated with prior stomach surgery. Possible associations between Dieulafoy lesions and alcohol intake and Dieulafoy lesions and the use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDS), and warfarin have been suggested.

Endoscopic techniques may be used to treat Dieulafoy lesions. These techniques may include the use of electrical current, heat, or argon gas to cause the blood to clot; injection of medications such as epinephrine; or the placement of bands or clips to close off the blood vessels. Angiography can also be used to treat the abnormal blood vessels (embolization). In some cases, surgery, either alone or in combination with endoscopic techniques, may be indicated.