The pathogenesis of large bowel diverticula.

DIVERTICULA of the alimentary tract may be congenital or acquired. The congenital variety is composed of all coats of the intestinal wall and is said to be a "true" diverticulum. The acquired variety may be either "true" or "false" depending on whether or not protrusion of the muscle coats of the intestinal wall occurs with the mucous membrane. Although the majority of acquired diverticula are "false", an investment from all coats is probably very frequent in the earliest stages of formation (Telling and Gruner, 19,17). It is generally agreed that colonic diverticula are of the acquired variety but in the caecum an isolated diverticulum of the congenital type may occur.