colonoscopy medical procedure

colonoscopy polyp intestine bowel sigmoidoscopy endoscopy familial adenomatous polyposis fap colon endoscope large colonoscope exam medical procedure pain inflammation system endoscopic treatment minimally invasive disorder inflated tunnel nonsurgical sphincter fibers anatomical digestive illustration test anus rectum tissue cancer gastrointestinal inflammatory disease ibd screening doctor endoscopist gastroenterologist colitis chronic vector