Bladder augmentation using colonic patches is being increasingly performed and a substantial risk of neoplasia in such patches has been reported. We present the case of a 62-year-old man who developed a large flat adenoma in the colonic mucosa of an augmented bladder. The adenoma was indigo-carmine dye sprayed and completely resected via a cystoscope using an endoscopic mucosal resection technique. We discuss how methods used at colonoscopy to detect and remove early neoplastic lesions may readily be employed during colonic patch surveillance at cystoscopy.