Anyone had Endoscopic Submucosal Dissection for residual Colon Cancer?

After finishing Folfox Treatment for rectal Cancer there is still a residual polyp remaining which the surgeon suggested the surgeon suggested the surgery which would leave mom with a colostomy bag. After talking some more about alternative options since biopsy was negative and CEA blood level had dropped, he suggested there was another option called Endoscopic Submucosal Dissection - where during a Colonoscopy procedure they scoop/cut out the remaining polyp and then perform pathology to determine if any cancer below the polyp or not. Hoping for the best and wanted to see if anyone else had been through this procedure. Thanks!