Supplementary Material for: A Rapid Development of Post-Colonoscopy Appendicitis Within Twelve Hours: A Case Report

Introduction
Colon cancer has seen a steady decline in incidence due to increased colonoscopy use. We can assume that this increased use, results in a higher incidence of post-colonoscopy complications such postpolypectomy syndrome, perforation and post-colonoscopy appendicitis (PCA). In this report we present a case of post-colonoscopy appendicitis presenting to the emergency department within 12 hours of a screening colonoscopy.
Case Presentation
Our patient, a 77-year-old male, underwent an uncomplicated screening colonoscopy and was discharged home after briefly being monitored without any complaints. Later that day, the patient presented to the emergency department complaining of acute generalized abdominal pain. On presentation, the patient was found to be hypertensive and febrile with a distended abdomen with right lower quadrant tenderness on examination. Laboratory investigations noted an elevated white blood cell count with no evidence of acute appendicitis or focal inflammatory changes on contrast-enhanced abdominal and pelvic computer tomography. The patient was subsequently admitted and, developed worsening right lower quadrant abdominal pain and distention overnight. Due to this worsening clinical condition, the decision was made to proceed with a diagnostic laparoscopy. After frank pus was found laparoscopically around the cecum and appendix, it was then converted to an exploratory laparotomy. Subsequently, a perforated gangrenous appendix was found with an erythematous and indurated cecum.
Conclusion
Major complications of colonoscopy can include perforation and/or post-colonoscopy bleeding which have been shown to have a respective incidence of 0.21% and 0.1%. With the anticipated rise in the number of colonoscopies, much rarer complication such as PCA with an incidence of less than 0.05% will be seen more frequently. Due to its nonspecific presentation, it is necessary for providers to consider PCA as an important differential for all patients presenting with abdominal pain after a colonoscopy.