In colonoscopy;  diagnosis of anal channel disorders such as anal fissure, fistula, hemorrhoids, lesions such as diverticulum ulcer, tumors can be placed. Colonoscopy should be done for people with colon cancer in the family, people who bleed from anus or detected with fecal occult blood, changes in bowel habits in the direction of constipation or diarrhea, for the monitoring of patients who are previously diagnosed with colorectal cancer or polyp and treated, people with inflammatory bowel disease (ulcerative colitis, Crohn's disease), unexplained weight loss and people with anemia complaint. Biopsies can be taken from suspected areas for sending to pathology.