Immune checkpoint inhibitor gastritis is often associated with concomitant enterocolitis, which impacts the clinical course.

Immune checkpoint inhibitors are effective anticancer treatments, but can cause inflammatory toxicities, including of the stomach (gastritis), intestine, and colon. Limited information is available on gastritis triggered by these agents. Adult patients with cancer who were treated with immune checkpoint inhibitors and had an upper gastrointestinal endoscopy with biopsies of the stomach were examined. More than two-thirds (70%) of people with checkpoint inhibitor gastritis also had inflammatory changes of the small intestine and/or colon. Compared with patients with isolated checkpoint gastritis, the subgroup with concomitant enteritis/colitis more frequently had abdominal pain, diarrhea, needed steroids, and/or needed to pause or stop antitumor therapy.