Diverticular Disease of the Stomach and Small Bowel By Joel A Baum, MD, Icahn School of Medicine at Mount Sinai; Rafael Antonio Ching Companioni, MD, HCA Florida Gulf Coast Hospital Reviewed / Revised Oct 2022 View Patient Education Key Points Diverticula are saclike mucosa-lined pouches that protrude from a tubular structure (see also Definition of Diverticular Disease).