Meckel’s Diverticulum is a common congenital anomaly of the small intestine, representing a remnant from early fetal development. While many individuals live their entire lives unaware of its presence, this pouch can sometimes lead to various health problems. Understanding its origin and how it can manifest is important for recognizing potential symptoms.
Understanding Meckel’s Diverticulum
Meckel’s Diverticulum is a small pouch or bulge located on the wall of the small intestine, specifically the ileum. This anatomical variation arises from the incomplete closure of the omphalomesenteric (vitelline) duct during fetal development. This duct normally connects the developing gut of the fetus to the yolk sac, providing nutrients in the earliest stages of growth. Typically, this connection fully obliterates by weeks 8-10 of gestation. When it fails to do so completely, a Meckel’s Diverticulum forms as a leftover remnant.
This condition is the most common congenital anomaly of the gastrointestinal tract, affecting approximately 2% of the general population. The diverticulum is usually found within about two feet (45-90 cm) of the ileocecal valve, which is the junction between the small and large intestines. A notable feature is its potential to contain ectopic tissue—tissue types not normally found there. Most commonly, this ectopic tissue is gastric (stomach-like) or pancreatic tissue, found in about 50% of cases, with gastric mucosa being present in 60% to 85% of these instances.
How Meckel’s Diverticulum Manifests
Most individuals with Meckel’s Diverticulum never experience symptoms. For the small percentage who do develop problems, symptoms usually appear before two years of age. When issues arise, they stem primarily from the presence of ectopic tissue or mechanical complications.
One of the most frequent symptoms, particularly in children, is gastrointestinal bleeding. This often presents as painless rectal bleeding (bright red, maroon, or black and tarry). The bleeding occurs because the ectopic gastric tissue within the diverticulum produces acid, similar to the stomach. This acid can cause ulcers in the adjacent intestinal lining, leading to blood loss.
The diverticulum can also become inflamed (Meckel’s diverticulitis). This inflammation often mimics the symptoms of appendicitis, causing abdominal pain, typically around the navel or in the lower right abdomen, along with nausea, vomiting, and fever. This occurs when stool or other contents get trapped inside the pouch, leading to bacterial infection and irritation.
Intestinal obstruction is another complication. The diverticulum may act as a lead point for intussusception, where one segment of the intestine telescopes into another. It can also cause a volvulus, a twisting of the intestine around the diverticulum, or lead to the formation of fibrous bands (adhesions) that block the bowel. These obstructions result in severe abdominal pain, bloating, vomiting, and an inability to pass stool. Rarely, prolonged inflammation or ulceration can lead to perforation and peritonitis—a life-threatening abdominal infection.
Diagnosing and Treating Meckel’s Diverticulum
Diagnosing Meckel’s Diverticulum is challenging due to varied symptoms resembling other abdominal conditions. Since most individuals with the condition are asymptomatic, it is often discovered incidentally during surgery for other reasons. However, when symptoms like unexplained abdominal pain or bleeding occur, specific diagnostic tools become important.
The most specific diagnostic test is the Meckel’s scan (Technetium-99m pertechnetate scan). This nuclear medicine procedure injects a radioactive tracer into the bloodstream. The tracer is absorbed by the ectopic gastric mucosa present in the diverticulum, allowing it to be visualized with a special camera. While highly accurate for detecting ectopic gastric tissue, false-negative results can occur if there is insufficient ectopic mucosa or if the patient is actively bleeding heavily. Other imaging studies, such as CT scans, MRI, or angiography, may be used to identify complications like obstruction or to locate the source of bleeding.
For symptomatic Meckel’s Diverticulum, surgical removal is the standard treatment. This procedure, a diverticulectomy, excises the pouch from the small intestine. In some cases, if the base of the diverticulum is wide or if there is significant damage to the adjacent bowel, a small segment of the intestine may also be removed and then reconnected. The surgery can often be performed using minimally invasive laparoscopic techniques, which typically lead to quicker recovery times.
The management of incidentally discovered, asymptomatic Meckel’s Diverticulum is debated among medical professionals. The decision to remove it prophylactically often depends on factors such as the patient’s age, the characteristics of the diverticulum (like its length or the presence of ectopic tissue), and the potential risks of surgery versus the lifetime risk of complications. Successful treatment generally leads to an excellent prognosis, with rare symptom recurrence.