IntroductionEndoscopic removal of colorectal polyps is used as first-line treatment for reducing incidence of colorectal cancer and cancer-related mortality.(1) Colonoscopy is a safe procedure in general but there is a chance of complication. Complications are more likely to happen in colonoscopy with cautery. As the procedure gets more complex, the higher rate of complications is reported.(2) Perforation and post-colonoscopy hemorrhage are the most common complications.Local infection is one of colonoscopy complications; however, it is rare indeed. Perianal abscess and Fournier’s gangrene have been described after colonoscopy. The mechanism is local mechanical trauma.(3) Intraperitoneal and retroperitoneal abscess formation are also described in a few case reports as a result of colonoscopy.(4, 5) As far as we know, there is no report of rectus abdominis muscle abscess after colonoscopy. In this article, we want to present a case of rectus abdominis muscle abscess after colonoscopy completed with applying abdominal pressure techniques.