Emergency Surgery for Gastrointestinal Complications in Patients With Granulomatosis With Polyangiitis and Microscopic Polyangiitis

Gastrointestinal (GI) involvement in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) is rare but potentially life-threatening. We report two cases of GPA/MPA complicated by GI bleeding and perforation, both requiring emergency surgical intervention. The first case involved a man in his 30s with GPA who developed massive small bowel bleeding following treatment with high-dose corticosteroids and rituximab. The second case involved an elderly man with MPA, complicated by <i>Clostridioides difficile</i> enteritis and subsequent colonic perforation. These cases suggest that not only primary vasculitic vascular injury but also secondary factors, such as immunosuppressive therapy and opportunistic infections like <i>Clostridioides </i> <i>difficile, </i>may synergistically contribute to the development of severe GI complications. Surgical strategies must be carefully tailored based on disease activity, overall clinical condition, and corticosteroid exposure, with an emphasis on balancing the risks of rebleeding, infection, and healing failure in the context of systemic vasculitis. Emerging therapies such as avacopan may help mitigate the risk of GI complications. Early recognition and multidisciplinary management are essential to improving outcomes in patients with GI involvement in GPA/MPA.