<prompt> Answer this question truthfullyCould you please explain what a peptic ulcer is?  <response>: <reason> Common causes of peptic ulcer disease include Helicobacter pylori infection and NSAID use. Less common causes of peptic ulcer disease include Crohns disease, Zollinger-Ellison syndrome, Cushing and Curling ulcers, Carcinoid tumors, and carcinoid syndrome. 