Intraluminal pressure for any given colon diameter is thus higher in older patients than in younger patients. Some patients with diverticulosis have myochosis, a corrugation and thickening of the wall of the sigmoid colon. Myochosis narrows the lumen, predisposing the colon to segmentation and high pressures during contractions. There are no population-based studies of the prevalence of diverticulosis. Women were two to three times more likely than men to report diverticulosis, and whites were more likely than African Americans.
Unrecognized diverticulosis is more common than known diverticulosis.
In Western countries, diverticula involve predominantly the left colon. In Japan and other Asian countries, right-sided diverticula are more common than in the West. Diverticula are most often found incidentally during investigation of another condition. Patients who are asymptomatic at the time of diagnosis of diverticulosis are unlikely to develop complications such as diverticulitis. Diverticular disease and IBS are both common.