Diverticulitis is a common disease found in the digestive area, particularly in the large intestine. Diverticulitis develops from diverticulosis, which involves the formation of pouches on the outside of the colon. These pouches are called diverticula and diverticulitis results of one of these diverticula become inflamed. Small protruding sacs of the inner lining of the intestine can develop in any part of the intestine. They are most commonly found in the colon, specifically in the sigmoid colon. The diverticula increase in frequency after the age of 40. Symptoms of diverticulitis may include alternating diarrhea and constipation, and severe, intermittent cramps in the lower left side of the abdomen. Diverticulosis is very common, being found in more than half of Americans over the age of 60. Only a small percentage of these people will however develop the complication of diverticulitis.