Diverticula of the colon are a part of the colon, which protrude like small pouches beyond normal contours. Many of them are pseudo-diverticula that lack the muscular coats, and are prominences which the mucous membrane and submucosal layer protrude outwards from the fragile regions of the muscular coats. Diverticula of the colon are classified into, single and multiple, depending on the number, and when they are multiple they are called diverticulosis. Also among multiple diverticula (diverticulosis) which develop commonly in the sigmoid colon - descending colon, there are many cases that not only single diverticulosis merely occurs frequently, but hyperplasia of the muscular coats caused by muscle anomaly of the walls of the large intestine, and recurrent inflammation in the adipose tissues around the mesentery is associated. Meanwhile, when clinically diverticulosis is associated with inflammation, this is called diverticulitis, and when inflammation occurs in the surrounding tissue of diverticula, this is likely to be called peridiverticulitis. But they are mutually variable, according to the degree of lesions, acuteness or phase (stage of disease).