Post-polypectomy syndrome (PPS) is a complication that may arise after some colonoscopy procedures that require electrocoagulation, due to a transmural burn, which irritates the serous membrane. Its clinical presentation is similar to the one of intestinal perforation, but it has a favorable prognosis, and does not require surgical treatment. We report the case of a 55-year-old woman diagnosed with a polyp in the ascending colon, who was admitted for an endoscopic resection. After the procedure, she complained of nausea, emesis and abdominal pain in the right iliac fossa. She was transferred to the emergency department. An abdominal tomography showed cecal wall thickening without pneumoperitoneum. Therefore, the diagnosis of PPS was made and was managed with bowel rest, parenteral fluids and antibiotics, with full recovery. Despite of its low incidence, it is important to suspect this syndrome to avoid unnecessary surgical treatment and initiate medical management right away.