Recent Topics: Diverticular Disease
David F. Rhodes, M.D.
Introduction
Diverticular disease is common in the United States. While only 5% of the population is affected prior to age 40, 65% are affected by age 80. A majority of people with diverticulosis will not experience complications, however; 15-25 percent will develop diverticulitis and 5-15 percent will develop some type of bleeding.
Causes
The cause of diverticulosis is not fully understood. Colonic diverticula are small sac-like protrusions of the colon lining through the colon wall. They develop in areas of relative weakness where the small arteries supplying the colon penetrate the colon wall. Diverticula can develop anywhere in the colon, but in the United States and Europe, diverticula develop predominately in the lower or sigmoid colon. The higher pressures found in this part of the colon are thought to be responsible for this distribution. Many studies suggest that high fat, low fiber diets are associated with diverticulosis. Whether adding fiber to the diet can prevent formation of new diverticula is unknown, but countries with high fiber intake do have lower rates of diverticulosis.
Many people confuse the terms diverticulosis and diveticulitis. Diverticulosis implies only the presence of diverticula in the colon. Patients with diverticulosis usually have no symptoms related to the diverticula. Diverticulitis, on the other hand, refers to inflammation of one or more of the diverticula and is almost always associated with significant symptoms.
Symptoms
Typical symptoms of diverticulitis include pain and tenderness in the left lower abdomen, fever, constipation or diarrhea, urinary symptoms, and nausea sometimes with vomiting. The symptoms usually start abruptly and worsen over two or three days prior to the patient seeking medical care. The inflammation that leads to these symptoms is caused by a small, usually microscopic, perforation in a diverticulum. This small hole allows the bacteria that normally reside in the colon to escape into the surrounding tissues. Our body’s natural response to bacteria in these normally sterile tissues is an intense inflammatory response.
Treatment
Diverticulitis will resolve with antibiotic therapy alone in 75% of cases. Often it can be treated with oral antibiotics taken at home, though more severe cases may require treatment in the hospital. Complications from diverticulitis occur in up to 25% of cases. Complications can include abscess formation, obstruction, perforation, or fistula formation. Treatment of complications will often require surgery, though abscesses can often be treated with less invasive drainage procedures performed by a radiologist. A more difficult treatment decision is deciding when surgery is necessary when there has been no complication. A general rule is that surgery will be recommended when a patient has had three or more uncomplicated bouts of diverticulitis or has not responded to adequate medical therapy alone. Some authorities suggest that patients who develop diverticulitis prior to age 40 should undergo surgery during or after their first bout, but this is controversial.
Diagnosis
The diagnosis of diverticulosis is usually made by CT scan, lower endoscopy, or barium enema. The diagnostic test of choice during a suspected bout of acute diverticulitis is the CT scan. A CT scan can usually detect complications of diverticulitis as well as identify other diseases that may be mimicking diverticulitis. Lower endoscopy should be avoided during acute diverticulitis as it may worsen the symptoms or even lead to a complication. Once acute diverticulitis has been adequately treated, however, a colonoscopy should be performed. Colonoscopy is the most accurate method to evaluate the lumen of the colon and assess for the possibility of colon cancer, which will occasionally masquerade as diverticulitis. Colonoscopy also allows for determination of the extent of the diverticulosis.
Diverticular bleeding is not associated with diverticulitis. Bleeding from diverticula is usually painless. The amount of bleeding can vary from minor, to massive and life threatening. The most important consideration in the initial evaluation of a patient with painless rectal bleeding is to adequately resuscitate the patient with fluids and blood transfusions if necessary. Once the patient is stabilized, the source of the bleeding needs to be determined. This is usually accomplished by endoscopy. Diverticular bleeding will usually stop spontaneously. Occasionally, diverticular bleeding will not stop on its own. Options for treatment include several endoscopic therapies, radiological procedures that occlude the bleeding vessel, or surgery. As a general rule, endoscopic therapies are more useful in bleeding from the upper gastrointestinal tract than from colonic diverticula. Persistent or recurrent diverticular bleeding is usually best managed surgically or through specialized radiological procedures.
Most people who receive a diagnosis of diverticular disease will obtain advice from their well-intentioned friends, and often their doctor, to avoid certain foods. The list of prohibited foods will usually include nuts, seeds, and popcorn. Despite the ubiquitous nature of this advice, there is no scientific evidence to suggest that avoiding these foods will make any difference in the course of diverticular disease. Eating foods high in fiber and/or adding fiber supplements to the diet may have some benefits, but even this advice is based on modest evidence.
Dr. David F. Rhodes is a board certified gastroenterologist with Cabarrus Gastroenterology Associates, LLP in Concord, NC. Cabarrus GI provides high quality, personalized care to patients in Cabarrus and surrounding counties. Thomas T. Long, M.D., Frank S. Pancotto, M.D., David F. Rhodes, M.D., Thomas A. Dalton, M.D., Robert T. Foust, M.D., and Mark D. Aldous, M.D. are available for appointments Monday through Thursday, 8:30 a.m. to 4:30 p.m. and Friday 8:30 to 3:00 p.m. Call 704-783-1840 for further information.
