Multidisciplinary management of ulcerative colitis complicated by immune checkpoint inhibitor-associated colitis with life-threatening gastrointestinal hemorrhage: A case report.

BACKGROUND: Programmed cell death 1 (PD-1) inhibitors are immune checkpoint inhibitors (ICI) that have demonstrated significant efficacy in treating various advanced malignant tumors. While most patients tolerate treatment well, several adverse drug reactions, such as fatigue, myelosuppression, and ICI-associated colitis, have been reported. CASE SUMMARY: This case involved a 57-year-old male patient with ulcerative colitis complicated by hepatocarcinoma who underwent treatment with tirelizumab (a PD-1 inhibitor) for six months. The treatment led to repeated life-threatening lower gastrointestinal hemorrhage. The patient received infliximab, vedolizumab, and other salvage procedures but ultimately required subtotal colectomy due to uncontrollable massive lower gastrointestinal bleeding. Currently, postoperative gastrointestinal bleeding has stopped, the patient's stool has turned yellow, and his full blood cell count has returned to normal. CONCLUSION: This case highlights the necessity of early identification, timely and adequate treatment of ICI-related colitis, and rapid escalation to achieve the goal of improving prognosis.