Diverticulosis is the condition of having multiple pouches (diverticula) in the colon that are not inflamed. These are outpockets of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. Diverticula do not cause symptoms in most people. Diverticular disease occurs when diverticula become clinically inflamed, a condition known as diverticulitis. Diverticula typically occur in the sigmoid colon, which is commonplace for increased pressure. The left side of the colon is more commonly affected in the United States while the right side is more commonly affected in Asia. Diagnosis is often during routine colonoscopy or as an incidental finding during CT scan. It is common in Western countries with about half of those over the age of 60 affected in Canada and the United States. Diverticula are uncommon before the age of 40, and increase in incidence beyond that age. Rates are lower in Africa; the reasons for this remain unclear but may involve the greater prevalence of a high fiber diet in contrast with the lower-fiber diet characteristic of many Western populations. Signs and symptoms Some people with diverticulosis complain of symptoms such as cramping, bloating, flatulence, and irregular defecation. However, it is unclear if these symptoms are attributable to the underlying diverticulosis or to coexistent irritable bowel syndrome. Diverticular disease was found associated with a higher risk of left sided colon cancer. Bleeding Diverticular disease can present with painless rectal bleeding as bright red blood per rectum. Diverticular bleeding is the most common cause of acute lower gastrointestinal bleeding. However, it is estimated that 80% of these cases are self-limiting and require no specific therapy. Diverticulitis Infection of a diverticulum can result in diverticulitis. A recent study found that it happens only about 4% of the time. That contradicts the prevailing thinking that 10% to 25% of people with diverticulosis go on to develop diverticulitis. Tears in the colon leading to bleeding or perforations may occur; intestinal obstruction may occur (constipation or diarrhea does not rule this possibility out); and peritonitis, abscess formation, retroperitoneal fibrosis, sepsis, and fistula formation are also possible occurrences. Rarely, an enterolith may form. Infection of a diverticulum often occurs as a result of stool collecting in a diverticulum. It is defined as diverticular disease with signs and symptoms of diverticular inflammation. Clinical features of acute diverticulitis include constant abdominal pain, localized abdominal tenderness in the left lower quadrant of