A Meckel diverticulum is a saclike outpouching of the wall of the small intestine present in some children at birth.
About 3% of infants are born with a Meckel diverticulum. People can live their whole lives without ever knowing they have a Meckel diverticulum, but occasionally the abnormality can cause problems.
Over half the time, the diverticulum contains tissue like that of the stomach, pancreas, or both. If stomach tissue is present, it can secrete acid just like the stomach does. This acid may cause ulcers and bleeding of the nearby intestine. A Meckel diverticulum may also become inflamed (diverticulitis) or cause intussusception. Severe Meckel diverticulitis can occur at any age, but older children are most affected.
Symptoms and Diagnosis
Most children with a Meckel diverticulum have no symptoms, and many adults learn they have the condition only after surgeons discover it while performing surgery for another reason. The most common symptom among children younger than 5 years is painless rectal bleeding, which comes from ulcers in the small intestine caused by acid secreted by the diverticulum. Because of the bleeding, stools may appear bright red or brick-colored or currant jelly–colored because of a mixture of blood and mucus. Sometimes, stool appears black because of the breakdown of blood. Only rarely is the bleeding so severe that the child needs emergency surgery.
Diverticulitis caused by a Meckel diverticulum causes severe pain, abdominal tenderness, and sometimes vomiting and can easily be confused with appendicitis.
It is often difficult for doctors to diagnose a Meckel diverticulum. Blood tests, x-rays, computed tomography (CT), and barium enemas are not usually helpful. The best test is an imaging study called a Meckel radionuclide scan, in which a small amount of a harmless radioactive substance is given by vein (intravenously). The substance is picked up by cells in the diverticulum, which can then be seen using a radiation-sensing camera.
No treatment is needed for a diverticulum that does not cause symptoms. A bleeding diverticulum or one that causes symptoms must be surgically removed. If a Meckel diverticulum is found in a child during an operation being performed for another reason, it is typically removed to prevent future complications.
Last full review/revision November 2012 by William J. Cochran, MD