Diverticulitis is a condition in which diverticuli in the colon rupture. The rupture results in infection in the tissues that surround the colon.
The colon (large intestine) is a long tube-like structure that stores and then eliminates waste material. Pressure within the colon causes bulging pockets of tissue (sacs) that push out from the colonic walls as a person ages. A small bulging sac pushing outward from the colon wall is called a diverticulum.
More than one bulging sac is referred to in the plural as diverticula. Diverticula can occur throughout the colon but are most common near the end of the left colon referred to as the sigmoid colon. The condition of having these diverticula in the colon is called diverticulosis.
A person with diverticulosis may have few or no symptoms. When a diverticulum ruptures and infection sets in around the diverticulum, the condition is called diverticulitis. An individual suffering from diverticulitis may have abdominal pain, abdominal tenderness, and fever. When bleeding originates from a diverticulum, it is called diverticular bleeding. A person who suffers the consequences of diverticulosis in the colon is referred to as having diverticular disease.
Diverticular disease is common in the Western world but is extremely rare in areas such as Asia and Africa. Diverticular disease increases with age. It is uncommon before the age of forty, and is seen in more than fifty percent of people over the age of 60 years in the United States.
Whereas most patients with diverticular disease have no or few symptoms, some patients will develop bleeding, rupture and infection (diverticulitis), constipation, diarrhea, abdominal cramps, and even colonic obstruction.
The muscular wall of the colon grows thicker with age, although the cause of this thickening is unclear. It may reflect the increasing pressures required by the colon to eliminate feces. For example, a diet low in fiber can lead to small, hard stools which are difficult to pass and which require increased pressure to pass. The lack of fiber and small stools also may allow segments of the colon to close off from the rest of the colon when the colonic muscle in the segment contracts.
The pressure in these closed-off segments may become high since the increased pressure cannot dissipate to the rest of the colon. Over time, high pressures in the colon push the inner intestinal lining outward (herniation) through weak areas in the muscular walls. These pouches or sacs that develop are called diverticula.
Most patients with diverticulosis have few or no symptoms. The diverticulosis in these individuals is found incidentally during tests for other intestinal problems. Twenty percent of patients with diverticulosis will develop symptoms related to diverticulosis.
The most common symptoms of diverticular disease include:
- abdominal cramping,
These symptoms are related to difficulty in passing stool through the left colon, which is narrowed by diverticular disease.
More serious complications include:
- collection of pus (abscess) in the pelvis,
- colon obstruction,
- generalized infection of the abdominal cavity (bacterial peritonitis),
- bleeding into the colon.
A diverticulum can rupture, and the bacteria within the colon can spread into the tissues surrounding the colon causing diverticulitis. Constipation or diarrhea may also occur. A collection of pus can develop around the inflamed diverticulum, leading to formation of an abscess, usually in the pelvis.
On rare occasions, the inflamed diverticula can erode into the urinary bladder, causing bladder infection and passing of intestinal gas in the urine. Inflammation in the colon can also lead to colonic bowel obstruction. Infrequently, a diverticulum ruptures freely into the abdominal cavity causing a life threatening infection called peritonitis.
Diverticular bleeding occurs when the expanding diverticulum erodes into a blood vessel at the base of a diverticulum. Rectal passage of red, dark or maroon-colored blood and clots occur without any associated abdominal pain. Blood from a diverticulum of the right colon may be black in color. Bleeding may be continuous or intermittent, lasting several days.
Patients with active bleeding usually are hospitalized for monitoring. Intravenous fluids are given to support the blood pressure. Blood transfusions are necessary for those with moderate to severe blood loss. In a rare individual with brisk and severe bleeding, the blood pressure may drop, causing dizziness, shock, and loss of consciousness.
In most patients, bleeding stops spontaneously and they are sent home after several days in the hospital. Patients with persistent, severe bleeding require surgical removal of the bleeding diverticula.
Doctors believe a low-fiber diet is the main cause of diverticular disease. The disease was first noticed in the United States in the early 1900's. At about the same time, processed foods were introduced to the American diet. Many processed foods contain refined, low-fiber flour. Unlike whole-wheat flour, refined flour has no wheat bran. Diverticular disease is common in developed or industrialized countries-particularly the United States, England, and Australia-where low-fiber diets are common.
The disease is rare in countries of Asia and Africa, where people eat high-fiber vegetable diets. Fiber is the part of fruits, vegetables, and grains that the body cannot digest. Some fiber dissolves easily in water (soluble fiber). It takes on a soft, jelly-like texture in the intestines. Some fiber passes almost unchanged through the intestines (insoluble fiber). Both kinds of fiber help make stools soft and easy to pass. Fiber also prevents constipation.
Constipation makes the muscles strain to move stool that is too hard. It is the main cause of increased pressure in the colon. The excess pressure causes the weak spots in the colon to bulge out and become diverticula.
Diverticulitis occurs when diverticula become infected or inflamed. Doctors are not certain what causes the infection. It may begin when stool or bacteria are caught in the diverticula. An attack of diverticulitis can develop suddenly and without warning.
Most patients with diverticulosis have minimal or no symptoms, and do not require any specific treatment. A high fiber diet and fiber supplements are advisable to prevent constipation and perhaps prevent the formation of more diverticula.
Patients with mild symptoms of abdominal pain due to muscular spasm in the area of the diverticula may benefit from anti-spasmodic drugs such as:
- chlordiazepoxide (Librax),
- dicyclomine (Bentyl),
- atropine, scopolamine, phenobarb (Donnatal),
- hyoscyamine (Levsin).
Some doctors also recommend avoidance of nuts, corn, and seeds to prevent complications of diverticulosis. Whether these dietary restrictions are beneficial is uncertain.
When diverticulitis occurs, antibiotics are usually needed. Oral antibiotics are sufficient when symptoms are mild.
Some examples of commonly prescribed antibiotics include:
- ciprofloxacin (Cipro),
- metronidazole (Flagyl),
- cephalexin (Keflex),
- doxycycline (Vibramycin).
Liquid or low fiber foods are advised during acute attacks of diverticulitis. This is done to reduce the amount of material that passes through the colon, which at least theoretically, may aggravate the diverticulitis.
In severe diverticulitis with high fever and pain, patients are hospitalized and given intravenous antibiotics. Surgery is needed for patients with persistent bowel obstruction or abscess not responding to antibiotics.