Diverticular Disease

Diverticular disease is a disorder in which bulging pouches (diverticula) in the GI wall push the mucosal lining through the surrounding muscle. The most common site for diverticula is in the sigmoid colon, but they may develop anywhere, from the proximal and of the pharynx to the anus. Other typical sites are the duodenum, near the pancreatic border or the ampulla of vater, and the jejunum. Diverticular disease of the stomach is rare and may be a precursor of peptic or neoplastic disease. Diverticular disease of the ileum (Meckel's diverticulum) is the most common congenital anomaly of the GI tract.

Diverticular disease has two clinical forms. In diverticulosis, diverticula are present but don't cause symptoms. In diverticulitis, a far more serious disorder, diverticula become inflamed and can cause complication, such as obstruction, infection,and hemorrhage.

Diverticular disease is most common in adults age 45 and older. It affects 30% of adults over age 60.

Causes

Diverticular disease is very common in elderly people, being present in up to 80 per cent of elderly individuals in Western countries. It is rare in people under 20 years of age and in developing countries.

Diverticular disease is thought to be caused by long-standing constipation. The large intestine produces solid stool from the remains of food after all the nutrients have been absorbed in the small intestine. Constipation increases pressure within the intestine and over many years this forces small areas of the lining of the intestine to weaken to form the small sacs or pouches.

Signs and Symptoms

Usually, the patient with diverticulosis is symptom-free. Occasionally, the history reveals intermittent pain in the left lower abdominal quadrant, which may be relieved by defecation or the passage of flatus. The patient may report alternating bouts of constipation and diarrhea. The assessment usually reveals no clinical findings. Rarely, palpation discloses abdominal tenderness in the left lower quadrant.

The patient with diverticulitis may have a history of diverticulosis, diagnosed incidentally on radiography of the GI tract. Investigation of his dietary history commonly reveals low fiber consumption. He may report recent consumption of foods containing seeds of kernels, such as tomatoes, nuts, popcorn, and strawberries, or indigestible roughage, such as celery and corn. Seeds and undigested roughage can block the neck of a diverticulum, causing diverticulitis.

The patient with diverticulitis typically complains of moderate pain in the left lower abdominal quadrant, which he may describe as dull or steady. Straining, lifting, or coughing may aggravate his pain. Other signs and symptoms include mild nausea, flatus, and intermittent bouts of constipation, sometimes accompanied by rectal bleeding. Some patients report diarrhea.

On inspection, the patient with diverticulitis may appear distressed. Palpation may confirm his reports of left lower quadrant abdominal pain. He may have a low-grade fever.

In acute diverticulitis, the patient may report muscle spasms and show signs of peritoneal irritation. Palpation may reveal guarding and rebound tenderness. Rectal examination may disclose a tender mass if the inflamed area is close to the rectum.

Diagnostic tests

Various tests may be used to establish the diagnosis, determine complications, and rule out other disorders such as cancer.

Results of barium studies confirm the diagnosis. An upper GI series confirms or rules out diverticulosis of the esophagus and upper bowel; a barium enema confirms or rules out diverticulosis of the lower bowel. Barium-filled diverticula can be single, multiple, or clustered like grapes and may have a wide or narrow mouth. Barium outlines, but doesn't fill, diverticula blocked by impacted stools. In patients with acute diverticulitis, a barium enema could rupture the bowel, so this procedure isn't done before the acute phase resolves.

Radiography may reveal colonic spasm if irritable bowel syndrome accompanies diverticular disease.

Biopsy may be used to rule out cancer. Colonoscopic biopsy isn't recommended during acute diverticular disease because of the strenuous bowel preparation it requires.

Blood studies may show leukocytosis and an elevated erythrocyte sedimentation rate in diverticulitis, especially if the diverticula are infected.

Stool test results show occult blood in 20% of patients with diverticulitis.

Treatment

Patient management depends on the type of diverticular disease and the severity of symptoms. Asymptomatic diverticulosis generally requires no treatment. Intestinal diverticulosis that causes pain, mild GI distress, constipation, or difficult defecation may respond to a liquid or low-residue diet, stool softeners, and occasional doses of mineral oil. These measures relieve symptoms, minimize irritation, and lessen the risk of progression to diverticulitis. After pain subsides, patients also benefit from increased water consumption (eight glasses per day), a high-residue diet, and bulk medication such as psyllium.

Treatment for patients with mild diverticulitis with­out signs of perforation is intended to prevent constipation and combat infection. Therapy may include bed rest, a liquid diet, stool softeners, a broad-spectrum antibiotic, meperidine to control pain and relax smooth muscle, and an antispasmodic, such as propantheline, to control muscle spasms.

For patients with more severe diverticulitis, treatment consists of the above measures and I.V. therapy. A nasogastric (NG) tube to relieve intra abdominal pressure is usually required, and the patient is allowed nothing by mouth.

Patients who hemorrhage need blood replacement: and careful monitoring of fluid and electrolyte balance. Such bleeding usually stops spontaneously. If it continues, angiography for catheter placement and infusion of vasopressin into the bleeding vessel is effective. Rarely, surgery may be required.

A colon resection to remove a diseased segment of intestine may be required to treat patients with diverticulitis that is unresponsive to medical treatment or causes severe recurrent attacks in the same area.

Prevention

Choosing a diet with plenty of bulk may help prevent diverticulosis. People who have diverticulosis should eat a relatively high-fiber diet. Food supplements, such as psyllium, that serve to increase bulk may be recommended to move the stool through the colon at a normal rate.