Chronic diarrhea is a commonly encountered complaint and a principal cause of health care utilization worldwide. Although there are various etiologies of chronic diarrhea, McKittrick-Wheelock syndrome is a rare syndrome defined as a large villous adenoma with secretory diarrhea causing severe fluid imbalances. We report a case of a patient with McKittrick-Wheelock syndrome who was successfully treated with endoscopic resection. Our case aims to add information to the current literature supporting the endoscopic management of McKittrick-Wheelock syndrome.