Meckel's diverticulum is a small outpouching extending from the wall of the intestine and located in the lower portion of the small intestine. The pouch is a remnant of tissue from the embryonic development of the digestive system. The lining of this pouch is made up of either pancreatic tissue or acid-secreting tissue such as that seen in the stomach.
Meckel's diverticulum is the most common congenital (present at birth) abnormality of the digestive system. It is present in 2% of the population.
Complications from Meckel's diverticulum can develop at any age, and it is estimated that there is a 4 to 6% lifetime risk of complications occurring. However, this risk decreases with age. Infants and children appear to be at highest risk for complications, with over 50% of symptomatic Meckel's diverticula occurring in children less than 2 years of age.
An increased incidence of Meckel's diverticula is seen in association with other congenital anomalies, including:
Most people with this abnormality do not develop symptoms or problems. However, in some individuals, the secretion of acid by Meckel's diverticulum may cause peptic ulcers in the small intestinal lining. These ulcers can bleed or perforate (rupture), causing intestinal waste products to leak into the abdomen. This can result in a serious abdominal infection called peritonitis.
Meckel's diverticulum can also cause intestinal obstruction. It can do this by infolding on itself into the passageway of the intestine (intussusception). A portion of small intestine may also twist around an anchored Meckel's diverticulum. This is known as segmental volvulus and is associated with compromised blood supply and intestinal obstruction.
When the intestine develops an ulcer, significant bleeding can occur, resulting in anemia (low red blood cell count). Rapid blood loss can be associated with shock, which is life threatening. Intestinal obstruction and serious infection may also occur.
Symptoms occur only if the diverticulum bleeds, becomes infected or causes an obstruction, and they are twice more common in males than in females. The symptom most commonly seen in young children is painless rectal bleeding. The color of blood may vary from bright red to dark red or maroon to black tarry. While symptoms of infection and blockage generally occur before adolescence, they can appear at any time in life and can cause mild to severe abdominal pain and discomfort.
A symptomatic Meckel's diverticulum should be removed with an operation. This operation can be performed using either an open or a laparoscopic surgical approach. With both approaches, Meckel's diverticulum is resected (removed), the ulcerated area is identified, and the bleeding is stopped.
After recovery, resection of Meckel's diverticulum generally has no effect on gastrointestinal functioning or nutrition.