Acute appendicitis following colonoscopy.

To the Editor: Eight instances of appendicitis as a complication of colonoscopy have been reported in the English literature. We observed 2 cases of appendicitis shortly following colonoscopy with therapeutic interventions in the vicinity of the appendiceal orifice. A 24-year-old man with inactive ulcerative colitis status post colonoscopy with biopsy 4 days prior was admitted for hematochezia and underwent a repeat colonoscopy. Adherent clot with active slow bleeding was noted at a biopsy site in the terminal ileum. Hemostasis was achieved via epinephrine injection and bipolar coagulation probe coagulation. Two days later, he presented with low-grade fever and lower abdominal pain. Physical examination demonstrated right lower quadrant tenderness with rebound, and white blood cell count was 15,700. An axial CT of the abdomen and pelvis with oral and intravenous contrast revealed a distended and elongated appendix consistent with acute appendicitis. His symptoms and examination did not improve on antibiotics, and the patient underwent appendectomy the following day with confirmation of the radiographic diagnosis. A 55-year-old man with a history of ulcerative colitis and hyperplastic polyps presented for colonoscopy after multiple sessile polyps were resected by flexible sigmoidoscopy 6 months prior. The mucosa from the rectum to hepatic flexure had a reticulated pattern of scarring and scattered pseudopolyps throughout, consistent with a history of severe colitis, now quiescent. Biopsies were obtained for surveillance in four quadrants every 10 cm. A 4-mm sessile polyp in the cecum was resected with diathermy snare. On pathology, the polyp was determined to be hyperplastic, and all surveillance biopsies showed evidence of chronic quiescent colitis without dysplasia. He presented the following morning with diffuse abdominal pain and chills since the prior evening. On examination, his temperature was 99.7(F, and he had right lower quadrant tenderness with rebound. A white blood cell count was 16,500. An axial CT scan with oral contrast showed a distended proximal appendix with adjacent intraperitoneal fat stranding. The cecal wall was indistinct with question of a small amount of adjacent air. The findings were thought to be consistent with acute appendicitis and possible concomitant cecal microperforation. The patient was managed conservatively with broad-spectrum antibiotics with gradual improvement over several days. It has been suggested that colonoscopy could result in appendicitis by forcing bowel contents into the appendix when insufflating the colon. Other possible mechanisms included local edema from trauma induced by the endoscope or intervention causing temporary obstruction of the appendiceal orifice. Appendicitis is a rare complication of colonoscopy. This poses a diagnostic challenge because the presentation of appendicitis is similar to the presentation of other complications of colonoscopy, such as perforation and postpolypectomy syndrome. Because of the higher risk of extended hospital stay and complications associated with late or misdiagnosed appendicitis, it is important that physicians be aware of this complication so that diagnosis and intervention can be made in a timely manner.