As gastroenterologists, we are well aware that the risks of colonoscopy include colonic perforation, bleeding, adverse events related to sedation and the possibility of a missed lesion. We report the case of an unusual complication of a man presenting with a Morgagni hernia immediately after a colonoscopy. A 59 year old man with past medical history significant for hypertension, history of a left pneumothorax and alcohol abuse, presents for a colonoscopy to evaluate weight loss and guaiac positive stools. Colonoscopy reveals a 3mm sessile transverse colon polyp, a 2.0 × 1.8 × 0.9cm pedunculated descending colon polyp with a 2.5cm stalk and a 4mm sessile descending colon polyp. All three polyps are removed by snare cautery. Pathology reveals two tubular adenomas and one tubulo-villous adenoma. Post-procedure, the patient complains of shortness of breath, epigastric abdominal pain and right-sided chest pain aggravated by deep inspiration. Physical examination reveals bowel sounds with diffuse abdominal tenderness but there are no signs of rebound or peritonitis. Laboratory data reveals an elevated white blood cell count of 12.7 with unremarkable liver chemistries, amylase, lipase and serum lactate. An abdominal roentograph reveals a large right-sided Morgagni-type diaphragmatic hernia. The patient undergoes laparascopic reduction of the herniated colon and omentum and subsequent repair of the anterior diaphragmatic defect via exploratory laparatomy. He has an uncomplicated post-operative course. Congenital diaphragmatic hernias occur in approximately 0.1 to 0.5 per 1000 births. Morgagni hernias represent 2–3% of all surgically-repaired diaphragmatic hernias. Although these hernias are commonly cited in the literature, this is the first report of a patient presenting with a Morgagni hernia after a colonoscopy. Significant abdominal pain associated with an elevated white blood cell count often raises the gastroenterologists' suspicion for a colonic perforation or post-polypectomy syndrome. Our case expands the differential diagnosis the clinician should consider in patients presenting with abdominal pain after a colonoscopy especially when associated with a pleuritic component.