What is Meckel Diverticulum
Meckel diverticulum is an abnormal pouch in the lower part of the small intestine. Before birth, a duct connects the small intestine to the cord that nourishes and supports the developing baby (umbilical cord).
Normally, this duct disconnects and disappears after the second month of pregnancy. However, if part of the duct stays attached to the small intestine, it can form a Meckel diverticulum pouch that will be present at birth (congenital abnormality).
The small intestine is the part of the digestive tract that receives food from your stomach. However, the Meckel diverticulum contains a lining that is similar to the lining of the stomach or pancreas. This lining can produce an acid that sometimes causes problems, such as ulcers or bleeding. If that happens, treatment is needed to correct the problem.
Meckel’s diverticulum is the most common anomaly of the gastrointestinal tract. It is a persistence of the omphalomesenteric duct at its junction with the ileum.
It can be remembered by the rules of 2: It occurs in 2% of the population; 2% develop complications; complications usually occur before 2 years of age; and it is located within 2 feet of the ileocecal valve. Approximately 50% of resected Meckel’s diverticula contain heterotopic gastric mucosa.
The most common complication of Meckel’s diverticulum is painless gastrointestinal bleeding, which occurs secondary to irritation or ulceration by hydrochloric acid produced by the gastric mucosa that lines the diverticulum.
A Meckel’s diverticulum is a congenital diverticulum or outpocketing of small intestinal mucosa that typically occurs in the middle-to-distal ileum, approximately 150 cm proximal to the ileocecal valve. It occurs in approximately 2% of the population. This congenital anomaly is clinically important because of its propensity to cause obscure GI bleeding, especially in children. The bleeding is secondary to intestinal ulceration from acid secreted by ectopic gastric mucosa lining the diverticulum. The bleeding typically occurs in children who present with painless LGIB. However, Meckel’s diverticulum is also in the differential diagnosis of obscure, painless, LGIB in adults. Patients usually present with dark red or maroon stools.
Meckel’s diverticular bleeding is diagnosed by a Meckel’s scan, in which 99 m technetium pertechnetate is administered intravenously. Nuclear scintigraphy is then performed to identify the ectopic gastric mucosa within the diverticulum by the selective attachment of the technetium pertechnetate to it. A Meckel’s scan is approximately 90% sensitive and 90% specific for bleeding from a Meckel’s diverticulum in children, but is less accurate in adults.
What are the causes?
This condition is caused by a congenital abnormality in the small intestine.
What are the symptoms?
Some people have no symptoms. In other people, the diverticulum causes bleeding or inflammation. Symptoms can also result if there is a hole (perforation) or blockage (obstruction) in the intestine. Symptoms may include:
- Stomach pain.
- Nausea and vomiting.
- Bloody stools.
How is this diagnosed?
This condition may be diagnosed during an imaging study that is done for another problem. Your health care provider may:
- Ask about your signs and symptoms.
- Do a physical exam.
- Order other tests, including:
- A technetium scan (Meckel scan). In this test, the chemical technetium is injected into your bloodstream. Then you have an X-ray to check whether the technetium fills the Meckel diverticulum pouch.
- A CT scan.
Meckel’s diverticulum is detected by a nuclear medicine scan with technetium-99m ( 99m Tc) pertechnetate. The radiotracer accumulates within the diverticulum, usually appearing at approximately the same time as activity appears within the stomach, with gradually increasing intensity, thereby verifying the presence of ectopic gastric mucosa.
How is this treated?
Treatment for this condition depends on your symptoms. If you have bleeding, your health care provider may recommend surgery to remove the diverticulum and possibly a small section of your small intestine. No treatment is needed if you have no symptoms.
Contact a health care provider if:
- You have a fever.
- You have difficulty passing stool (constipated).
- Your symptoms get worse.
- You develop new symptoms.
Get help right away if:
- You have severe pain in the abdomen.
- You have vomiting that does not stop.
- You have dark or bright red blood in your stools.
- Meckel diverticulum is an abnormal pouch in the lower part of the small intestine that is present at birth.
- The Meckel diverticulum contains a lining that is similar to the lining of the stomach or pancreas. This lining can produce an acid that sometimes causes problems, such as ulcers or bleeding.
- Treatment of the condition depends on your symptoms. If you do not have symptoms, treatment will not be necessary.
- If you have bleeding, your health care provider may recommend surgery to remove the diverticulum and possibly a small section of your small intestine.