Orally administered Qing-dai, called indigo naturalis in Latin, is reportedly useful for the treatment of ulcerative colitis. We herein describe two patients with ulcerative colitis who developed colitis with wall thickening and edematous changes during oral administration of the powdered form of Qing-dai. In Case 1, a 35-year-old man developed colitis similar to ischemic colitis with bloody stool that recurred each time he ingested Qing-dai. He had no signs of recurrence upon withdrawal of Qing-dai. In Case 2, a 43-year-old woman underwent ileocecal resection for treatment of an intussusception 2 months after beginning oral administration of Qing-dai. Edema and congestion but no ulceration were present in the mucosa of the resected specimen. Both patients exhibited abdominal pain with bloody diarrhea, and abdominal computed tomography showed marked wall edema affecting an extensive portion of the large bowel.
Keywords: Adverse effect; Colitis; Indigo naturalis; Intussusception; Qing-dai.