Peritoneal dialysis (PD) is associated with the development of various complications, such as exit site infection or peritonitis, and rarely, intestinal obstruction in prolonged PD patients with recurrent peritonitis. However, post-colonoscopy acute intestinal obstruction has not been reported in PD patients to date. Herein, we report a case of severe ileus after a colonoscopy without previous episodes of peritonitis in a PD patient. A 51-year-old man undergoing PD for 7 years visited our emergency department due to severe abdominal pain and vomiting after colonoscopic polypectomy. A simple abdominal radiography and abdominal computed tomography showed ileus with collapsed distal ileal loop. A peritoneal dialysate study revealed no evidence of peritonitis. The patient was treated with decompression therapy, and ileus was successfully treated without complications. This case suggests that it is not only necessary to prevent peritonitis, but also important to monitor the development of ileus after colonoscopy in PD patients.