Meckel’s Diverticulum
Meckel’s Diverticulum
Research and general acceptance
Definition
A Meckel’s diverticulum is a small pouch about 2 inches 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.
Fabricius Hildanus first described the birth defect in 1598, but the condition is named for Johann F. Meckel, a German anatomist who was the first to note that the condition occurred during the embryonic stage of development.
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,
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.
intestinal blockages, or inflammation. New-borns 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:
- Blood tests. Blood tests, such as hematocrit and hemoglobin levels, to check for anemia (low number of red blood cells in the body) or stool smear tests to check for blood may be used. These test results cannot be used to directly diagnose Meckel’s diverticulum, but they may point to bleeding that is indicative of the condition.
- Nuclear scans. In non-emergency situations, doctors can inject dye into the outer opening of the belly button while examining the intestinal tract with a nuclear scan. The injected dye collects at bleeding sites or in stomach tissue, so if the doctors see blood or stomach tissue in the lower intestines, they will be able to diagnose Meckel’s diverticulum.
- Barium studies. Although barium studies are typically used in the diagnosis of digestive disorders, evidence suggests that using barium is unreliable in detecting Meckel’s diverticulum.
- Rectosigmoidoscopy. Physicians may also use a small flexible tube with a camera on the end, called a sigmoidoscope, to evaluate the rectum and colon for blockages, bleeding, or other problems.
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 high-fiber 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 improbably anyway.
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.
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 diverticu-lum 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
PERIODICALS
McKay R. High incidence of symptomatic Meckel’s diverticulum in patients less than fifty years of age: an indication for resection. American Surgeon, 2007 Mar 73(3): 271-5.
Sagar J, Kumar V, Shah DK. Meckel’s diverticulum: a systematic review. Journal of the Royal Society of Medicine, 2006 Oct;99(10):501-5.
ORGANIZATIONS
American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000. <http://www.aap.org>
QUESTIONS TO ASK YOUR DOCTOR
- How serious is my condition?
- Will I need surgery to treat my condition?
- How longwill it take me to recover after surgery, and what can I expect after recovery?
- What dietary changes will I need to make after treatment?
- Are there any long-term changes I need to make after surgery for Meckel’s diverticulum?
- My child is undergoing surgery. Are there any complications associated with pediatric surgery for Meckel’s diverticulum that I need to be concerned about?
American College of Gastroenterology. PO Box 3099, Alexandria, VA 22302. (800) HRT-BURN. <http://www.acg.gi.org>
American Gastroenterological Association. 7910 Wood-mont Ave., 7th Floor, Bethesda, MD 20814. (310) 654-2055. <http://www.gastro.org>
American Pediatric Surgery Association. 60 Revere Drive, Suite 500, Northbrook, IL 60062. (847) 480-9576. <http://www.eapsa.org>
National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, MD 20892. (800) 891-5389. <http://digestive.niddk.nih.gov>
Amy L. Sutton