Meckel's Diverticulum

Definition

A Meckel's diverticulum is a small pouch about 2 inches (5.08 cm) long that develops near the junction of the small and large intestines. Meckel's diverticulum occurs due to an abnormality in early fetal development. It is the most common birth defect that occurs in the digestive system.




Meckel's diverticulum, is a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk), and is the most frequent malformation of the gastrointestinal tract.





Meckel's diverticulum, is a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk), and is the most frequent malformation of the gastrointestinal tract.
(BiophotoAssociates/Science Source)

Origins

After conception, small ducts and structures connect the intestines and the stomach. As fetal development progresses and the intestines begin to lengthen and narrow, the ducts smooth out and usually disappear by about seven weeks after conception. In the case of Meckel's diverticulum (and other intestinal abnormalities, including cysts and fistulas), however, the ducts fail to disappear into the intestinal tissue and instead form small pouches.

These pouches have their own blood supply and may contain tissue from the pancreas, jejunum, duodenum, colon, rectum, or endometrium. Most commonly, however, the pouch contains stomach tissue in about 80% of cases.

Meckel's diverticulum is estimated to occur in about 2% of the population. The condition occurs about equally in males and females, but males are two to three times more likely to develop complications.

Most people with Meckel's diverticulum do not experience symptoms and never know that they have the condition. Doctors may discover the condition when performing diagnostic tests for other abdominal conditions.

Description

Symptoms of Meckel's diverticulum usually develop in children by 2 years of age, and people over the age of 10 years rarely have symptoms of the condition.

The most common symptoms associated with Meckel's diverticulum involve bleeding into the intestines, intestinal blockages, or inflammation. Newborns are more likely to experience intestinal blockage, whereas older infants and young children typically experience bleeding as the primary symptom. In adults, intestinal blockage is the most common complication associated with Meckel's diverticulum.

Bleeding from Meckel's diverticulum occurs when the stomach tissue in the lower intestine begins to secrete acid. Normally, stomach cells secrete acid to aid in food digestion, and the stomach's protective lining prevents the acid from damaging the digestive tract. However, when the stomach tissue in a Meckel's diverticulum begins secreting acid in the lower intestine, there is no protective lining. As a result, the acid ulcerates the intestinal walls, causing bleeding and pain.

A person with this condition may pass bloody stools, ranging in color from bright red, to maroon, to black and tarry. Although bleeding may subside for a while, it tends to recurs intermittently. The bleeding associated with Meckel's diverticulum may be so copious that blood transfusions are required.

A person with intestinal blockage due to Meckel's diverticulum may also experience abdominal pain or discomfort that ranges from mild to severe.

In rare cases, food or other swallowed objects may become trapped in the diverticulum pouch, leading to pain and swelling.

Symptoms of inflammation due to Meckel's diverticulum may appear similar to symptoms of appendicitis, an inflammation of the appendix. A person with Meckel's diverticulum may have a distended abdomen, cramping pain, and vomiting, much like a person with appendicitis. If surgery for suspected appendicitis reveals a normal appendix, physicians should check for Meckel's diverticulum in the patient at the time of surgery.

If a person's symptoms are not yet severe, doctors may use a variety of tests to aid in the diagnosis:

In most cases of symptomatic Meckel's diverticulum, surgical removal of the pouch is necessary. Surgery (physicians may refer to this as a resection) can restore blood supply to the intestines and eliminate symptoms of Meckel's diverticulum. If a person experiences heavy bleeding or severe abdominal pain, emergency surgery is usually required. Surgeons may actually diagnose the condition when the abdomen is cut open and can be inspected.

After surgery, a person with Meckel's diverticulum will receive intravenous fluids, pain medications, and sometimes antibiotics. Once the intestines begin making bowel sounds, which indicates that the gastrointestinal tract is working, a patient can usually begin taking food by mouth.

Function

Unlike diverticulosis, a condition in which small pouches form in the large intestine, there are no special dietary changes associated with the treatment or prevention of Meckel's diverticulum.

Patients with diverticulosis are advised to eat a high-fiber diet to prevent or lessen the severity of the condition. Fiber, the parts of grains, fruit, and vegetables that the body cannot digest, helps soften stool. For people with diverticulosis, soft stools are necessary to prevent blockages and constipation. Doctors think these diverticular pouches occur when a person is constipated and the excess pressure from the hard stool in the colon causes weakened portions of the colon to bulge out, forming diverticula (plural of diverticulum).

However, because Meckel's diverticulum is a congenital condition and the small intestinal pouches are unrelated to fiber intake or constipation, eating a highfiber diet—although recommended in general for good health—offers no particular beneficial advantage. Also, because most people without symptoms do not even know they have the condition, making dietary changes would be improbable anyway.

KEY TERMS
Anus—
The opening at the end of the intestines.
Appendectomy—
The procedure to surgically remove an appendix.
Appendicitis—
Inflammation of the appendix.
Barium—
A thick liquid that coats the stomach after consumption, allowing the inside of the stomach to show up on an x-ray.
Congenital—
Present at birth.
Crohn's disease—
Disorder that causes inflammation of the digestive tract.
Diverticula—
Small pouch in the colon.
Diverticulitis—
Having diverticula that have become infected or inflamed.
Diverticulosis—
Having diverticula.
Esophageal atresia—
Disorder of the digestive system in which the esophagus does not develop properly.
Omphalocele—
Birth defect that causes abdominal contents to protrude into the base of the umbilical cord.
Rectum—
The last eight to ten inches of the colon, through which wastes are removed from the body. The anus is part of the rectum.
Resection—
Surgical removal of a structure or organ.
Volvulus—
A twisted loop of bowel that causes obstruction.

Benefits

There are no benefits associated with Meckel's diverticulum. Special diets cannot alter the outcome or prevent the condition.

Precautions

There are no precautions that can be taken to prevent this condition. Meckel's diverticulum is not a hereditary condition, and most people do not even know they have it unless they begin experiencing symptoms.

However, research has shown that people with certain congenital anomalies may be more likely to develop Meckel's diverticulum. An increased incidence of the condition is seen in people with esophageal atresia, anus and rectal malformations, omphalocele, Crohn's disease, and other neurological and cardiovascular abnormalities.

QUESTIONS TO ASK YOUR DOCTOR

Rarely, intestinal cancer may develop in a person with Meckel's diverticulum, although this occurs more often in adults than children.

Risks

The risk of complications in patients who have not experienced symptoms is nearly zero. Patients who are not experiencing symptoms usually do not require surgical treatment.

Without treatment, a symptomatic person with Meckel's diverticulum can lose enough blood that he or she goes into shock. In some cases, the intestine could rupture and leak waste into the abdomen, increasing the risk of serious infection. In rare cases, the complications associated with Meckel's diverticulum may be life-threatening.

According to the American Pediatric Surgical Association, there is a less than 2% risk of complications associated with surgical treatment of Meckel's diverticulum. Post-surgical intestinal blockage from scar tissue occurs in just 5% to 9% of patients.

Gastrointestinal functioning and nutrition remain unaffected after treatment for Meckel's diverticulum. After surgery to remove the pouch and any intestinal blockage, symptoms will not recur. The prognosis for someone with Meckel's diverticulum is excellent.

Research and general acceptance

Treatment for a person with symptoms of Meckel's diverticulum is fairly straightforward and engenders little or no medical controversy.

When physicians are considering treatment options, determining whether to remove an asymptomatic Meckel's diverticulum may be controversial. Some research has indicated that age may play a role in the decision to remove a Meckel's diverticulum. A study in adults indicated that removal of asymptomatic diverticulum may benefit people under 50 years of age.

Resources

BOOKS

Boulton, Ralph, et al. A Colour Handbook of Gastroenterology. 2nd ed. Boca Raton, FL: CRC/Taylor & Francis, 2011.

Hebden, John, Mark Donnelly, and Mark Rickets. Gastrointestinal Problems: Your Questions Answered. London: Churchill Livingston, 2006.

Yamada, Tadataka, and John M. Inadomi, eds. Yamada's Handbook of Gastroenterology. 3rd ed. New York: John Wiley & Sons, 2013.

PERIODICALS

Pepper, V. K., A. B. Stanfill, and R. H. Pearl. “Diagnosis and Management of Pediatric Appendicitis, Intussusception, and Meckel Diverticulum.” Surgical Clinics of North America 92, no. 3 (June 2012): 505–26.

Sagar, Jayesh, Vikas Kumar, and D. K. Shah. “Meckel's Diverticulum: A Systematic Review.” Journal of the Royal Society of Medicine 99, no. 10 (October 2006): 501–5.

WEBSITES

American Academy of Family Physicians. “Meckel's Diverticulum.” http://familydoctor.org/familydoctor/en/diseases-conditions/meckels-diverticulum.html (accessed April 11, 2018).

MedlinePlus. “Meckel Diverticulum.” U.S. National Library of Medicine, National Institutes of Health. https://medlineplus.gov/ency/article/000234.htm (accessed April 11, 2018).

ORGANIZATIONS

American Academy of Family Physicians, 11400 Tomahawk Creek Pkwy., Leawood, KS, 66211-2680, (913) 906-6000, (800) 274-2237, Fax: (913) 906-6075, http://www.aafp.org .

American Academy of Pediatrics (AAP), 141 Northwest Point Blvd., Elk Grove Village, IL, 60007, (847) 434-4000, (800) 433-9016, Fax: (847) 434-8000, http://www.aap.org .

American Gastroenterological Association, 4930 Del Ray Ave., Bethesda, MD, 20814, (301) 654-2055, Fax: (301) 654-5920, member@gastro.org, http://www.gastro.org .

International Foundation for Functional Gastrointestinal Disorders, PO Box 170864, Milwaukee, WI, 53217, (414) 964-1799, (888) 964-2001, Fax: (414) 964-7176, iffgd@iffgd.org, http://www.iffgd.org .

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition, PO Box 6, Flourtown, PA, 19031, (215) 233-0808, Fax: (215) 233-3918, naspghan@naspghan.org, http://www.naspghan.org .

Amy L. Sutton

  This information is not a tool for self-diagnosis or a substitute for professional care.