Beyond the Scope: Unmasking Appendicitis Following Colonoscopy

Colonoscopy is a key diagnostic and therapeutic procedure in gastrointestinal practice, although rare complications such as post-colonoscopy appendicitis (PCA) may occur. We report the case of a 61-year-old woman who presented 24 hours after a screening colonoscopy with severe diffuse abdominal pain, fever, nausea, vomiting, and watery diarrhea. The procedure had been complicated by poor bowel preparation, with a Boston Bowel Preparation Score of 1-2-1 (right colon, transverse colon, and left colon, respectively; scores range from 0 to 3 per segment, with 0 indicating an unprepared colon and 3 indicating perfectly clean mucosa). Abdominal computed tomography (CT) revealed phlegmonous acute appendicitis with abscess formation and a calcified fecalith, in a pelvis-projecting appendix with a medial cecal position. An open appendectomy was performed, given the complex intraoperative findings and unfavorable anatomy for laparoscopic access. The patient recovered uneventfully and was discharged the following day. This case highlights the convergence of poor bowel preparation, fecalith impaction, and complicated appendicitis as a mechanistically informative triad and underscores the importance of maintaining a low threshold for CT imaging in patients with new abdominal symptoms following colonoscopy.