Gastrointestinal involvement at the onset of granulomatosis with polyangiitis: A case report.

A 30-year-old man had developed fever, bloody stools, and oral aphtha. Proteinase 3-antineutrophil cytoplasmic antibody level was 31 EU. Lower intestinal endoscopy revealed edematous mucosa with hemorrhage in the transverse colon. Biopsies of oral aphtha showed necrotizing angiitis with granuloma. Based on these findings, he was diagnosed with granulomatosis with polyangiitis (GPA). Digestive symptoms were remitted by treatment with prednisolone and azathioprine. GPA with digestive symptoms as the initial development is rare.