Meckel’s Diverticulum

What is Meckel’s diverticulum?

Meckel’s diverticulum is a common and often harmless birth defect that can occur in your baby’s small intestine. It affects 2% to 3% of all babies.

A diverticulum is a little pocket or indentation in the inside lining of one of your hollow organs, usually in your gastrointestinal (GI) tract. Diverticula can occur for various reasons and often go unnoticed. They may develop in your colon (large intestine) later in life.

Meckel’s diverticulum is a little different because it occurs during fetal development, and it can contain leftover tissue from development that wouldn’t ordinarily be there. Normal body tissue that grows in an abnormal place is called ectopic tissue.

This tissue can occasionally cause complications. For example, the pouch might contain stomach tissue that secretes stomach acid, which can cause bleeding ulcers.

What is Meckel’s diverticulum’s “rule of 2s”?

The “rule of twos” is a way of remembering basic facts and statistics about Meckel’s diverticulum, like:

• How common it is.
• How common its complications are.
• Who it affects.
• The ways it presents.

The rule goes like this:

• Meckel’s diverticulum occurs in 2% of the population.
• Only 2% of people who have it develop complications or symptoms.
• Symptoms usually appear in children under 2.
• Symptoms occur twice as often in those assigned male at birth (AMAB).
• It’s usually located about 2 feet from the lower end of the small intestine.
• It may have either of two types of ectopic tissue in it (stomach tissue or pancreatic tissue).

What are the symptoms or side effects of Meckel’s diverticulum?

You (or your child) won’t have symptoms unless you have complications. Meckel’s diverticulum by itself isn’t something you’d notice, and people can live their whole lives without knowing they have it. If complications do develop, they’re likely to do so in early childhood. But sometimes, they don’t show up until adulthood. The symptoms can be vague, and tracing them back to the cause can be a process.

Complications, and their symptoms, may include:

• Gastrointestinal bleeding. The most common complication is ectopic tissue secreting digestive juices that don’t belong in this part of the small intestine. This can lead to ulcers in your intestinal wall — open sores that bleed. Bleeding from your small intestine is often painless, but it’ll come out in your poop (stool). In children, it usually shows up as dark red blood in their stool. In adults, it may be tarry, black stool. If bleeding continues, you might develop anemia symptoms.
• Diverticulitis. Less commonly, you might develop inflammation and pain inside your Meckel’s diverticulum if it gets a bacterial infection. This might happen if passing stool gets stuck in the pouch. This can cause abdominal swelling and tenderness to the touch, especially near your belly button. If you or your child has ever had appendicitis, it might feel similar to that.
• Intestinal obstruction. Rarely, Meckel’s diverticulum may cause a bowel obstruction, partially or completely blocking the passage of solids through your small intestine. It can cause this in a few different ways. Sometimes, it has extra tissue attached to it that clogs the passageway. The pouch can also fold in on itself, causing another segment of the bowel to collapse into it. This is called intussusception. Bowel obstructions may cause bloating, cramping, nausea and vomiting.

How serious are these complications?

Complications of Meckel’s diverticulum could become life-threatening in severe cases. You’d probably notice symptoms before this stage. But if you didn’t, and they went untreated, they could escalate.

For example, constant bleeding from an ulcer could lead to significant blood loss and shock. An ulcer that erodes through your intestinal wall could leak bacteria, causing an infection that could become septic.

What causes Meckel’s diverticulum?

Meckel’s diverticulum occurs early in fetal development, when the yolk sac that fed the embryo during its first weeks is replaced by the placenta. The duct that once connected the yolk sac to the embryo (the vitelline duct or omphalomesenteric duct) detaches at this point, and the developing fetus is supposed to reabsorb it. But sometimes, it doesn’t detach or reabsorb completely, and a remnant is left over.

This remnant becomes Meckel’s diverticulum. The duct that once fed into the embryo’s small intestine remains as a small indentation in the baby’s small intestine. It can have different variations, too. Sometimes, a fibrous band of tissue remains attached to the diverticulum, which can cause an obstruction later. About 25% of the time, it has ectopic tissue in it, though scientists aren’t sure why.

What are the risk factors for this condition?

Meckel’s diverticulum appears to affect anyone. But you might be more likely to have it or to have complications from it if you also had another common congenital disorder, like esophageal atresia or anorectal malformation. Other risk factors include assigned male sex and age under 50 years.

How is Meckel’s diverticulum diagnosed?

Some people discover they have Meckel’s diverticulum by accident when they have an imaging test for some other reason. Other people discover it when they begin to have symptoms due to complications. Since these symptoms and complications have many possible causes, it can be a process to trace them back to Meckel’s diverticulum, especially in adults who’ve never had issues before.

Pediatricians are more likely to suspect Meckel’s diverticulum in young children who develop unexplained abdominal pain or painless rectal bleeding. Meckel’s diverticulum accounts for about half of all lower gastrointestinal bleeds in children under 2. When they suspect it, they’ll order tests to look for it. The tests they choose will depend on your child’s symptoms. Possible tests include:

• Meckel’s scan. This nuclear medicine imaging scan is usually the first choice for diagnosing Meckel’s diverticulum, especially when rectal bleeding is the primary symptom. It can detect ectopic stomach tissue in the diverticulum. A healthcare provider injects a small, safe dose of radioactive tracer material into your child’s vein and follows it with a gamma camera. If there’s ectopic stomach tissue in the diverticulum, it will absorb the tracer material and highlight itself.
• Mesenteric arteriography (angiogram). An imaging study of the blood flow through your mesenteric arteries can reveal the blood supply to Meckel’s diverticulum. If there’s an abnormal branch from your superior mesenteric artery to your lower small intestine, it can show where the diverticulum is located and reveal any active bleeding from the site. The blood supply doesn’t always look abnormal in everyone, though, so this doesn’t work every time.
• Endoscopy. If the above tests don’t reveal the diverticulum, a gastroenterologist may pass a tiny camera on a long tube into your small intestine (enteroscopy). Alternatively, you can swallow a tiny, pill-sized camera (capsule endoscopy). If your child can’t swallow it, a provider can place it in their GI tract endoscopically (through a tube passed down their throat) while they’re under sedation. After traveling through the intestines, the capsule will pass out in your poop.

What is the treatment for Meckel’s diverticulum?

If Meckel’s diverticulum causes complications, surgery can fix it. The procedure is called a small bowel resection. It just means cutting out the small piece of the bowel with the diverticulum in it. Most people won’t need surgery. In some cases, if your child has Meckel’s diverticulum with ectopic stomach tissue in it, your pediatrician might suggest removing it preventively, even if it hasn’t caused symptoms yet.

During surgery, your provider will also address any related complications, like an obstruction or perforation (hole). If you have a bleeding ulcer, it’ll be located somewhere outside of the diverticulum. Your surgeon will treat the ulcer separately to stop the bleeding. Most of the time, surgeons can treat Meckel’s diverticulum with laparoscopic surgery, which uses small incisions that heal quickly.

What can I expect after treatment?

Most people have a relatively short and easy recovery from Meckel’s surgery. If you had laparoscopic surgery, recovery might take two to three weeks. If you had open abdominal surgery, it might take six to eight weeks. There’s a low (5%) risk of complications from surgery that can make the recovery a little longer (like an infection). But after surgery, Meckel’s diverticulum won’t bother you or your child again.

Should I worry about Meckel’s diverticulum if I don’t have symptoms?

Most people will never have trouble with Meckel’s diverticulum. Only about 2% of people develop complications and symptoms. It’s a good idea to look out for these symptoms and consult a healthcare provider if you or your child develops unexplained abdominal discomfort, feeding difficulties or rectal bleeding. But if you’re an adult who’s never had complications from it, you probably never will.

A note from Cleveland Clinic

Meckel’s diverticulum is a tiny indentation in the inner wall of your small intestine. It usually doesn’t cause problems. Rarely, it may be the cause of mysterious abdominal pain or painless rectal bleeding, especially in children under 2. Knowing about it can help you recognize symptoms if they occur. If Meckel’s diverticulum does cause complications, a simple surgery can fix it.