A peptic ulcer is an open sore or raw area in the lining of the stomach (gastric) or the upper part of the small intestine (duodenal).
Review Date 4/2/2018
Updated by: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.