Overview of Diverticular Disease

Diverticula (singular is diverticulum) are small pouches or sacs that develop in the lining of an organ or canal in the body, such as the gastrointestinal tract (also called the GI tract or digestive tract). The presence of these pouches is called diverticulosis. Diverticulosis is a chronic (long lasting) condition that can be present at birth (congenital) or can develop later in life (acquired). When infection or inflammation occurs in one or more of these pouches, an acute (severe) condition called diverticulitis develops. Diverticulosis and diverticulitis also are called diverticular disease.

The GI tract includes the mouth, esophagus, stomach, small intestine, and large intestine. Diverticular disease can develop in any part of the digestive tract, but it affects the large intestine, or colon, most often.

The colon consists of the cecum (connects to the small intestine at the cecal valve), the ascending colon (vertical segment located on the right side of the abdomen), the transverse colon (extends across the abdomen), the descending colon (leads vertically down the left side of the abdomen), and the sigmoid colon (extends to the rectum). Diverticulitis develops in the left side of the colon about three times more often than the right side. The condition is most common in the sigmoid colon.

Diverticulitis occurs when undigested food or fecal matter collects in the diverticula and forms a hard mass (called a fecalith). This mass blocks blood flow to the diverticula, causes inflammation, and increases the risk for infection.

Incidence and Prevalence of Diverticular Disease

Diverticular disease is more common in North and South America, Europe, and Australia. According to the National Institutes of Health (NIH), about 10 percent of people over the age of 40 and 50% of people over the age of 60 in the United States have diverticulosis. Approximately 10–25 percent of people who have this condition develop diverticulitis.

Diverticular Disease Risk Factors and Causes

Age is a risk factor for diverticular disease. Over time, weaknesses can develop in the wall of the colon and increase the risk for diverticula. Other factors that can cause weaknesses and increase the risk for diverticulosis and diverticulitis include eating a low-fiber diet and heredity (genetics).

Genetics are thought to play a role in the development of diverticular disease. Although 70 percent of overall cases occur in the left side of the colon, the condition develops on the right side much more often (about 75 percent of cases) in Asians, including those who live in Western countries.

Regular use of certain medications (e.g., corticosteroids, nonsteroidal anti-inflammatory drugs [NSAIDs]) also may increase the risk for developing diverticular disease.

Inflammation and infection of small pouches or sacs (diverticula) in the walls of the gastrointestinal tract (e.g., small intestine, large intestine) cause diverticulitis.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 30 May 2007

Last Modified: 14 Sep 2015