Indications for Colonoscopy • Lower GI bleeding • Screening of colorectal cancers and polyps • Surveillance of colorectal cancers and polyps a. Colon cancer b. Surveillance after polypectomy c. Colorectal cancer post-resection surveillance d. Inflammatory bowel diseases • Acute and chronic diarrhea • Therapeutic indications for colonoscopy: a. Excision and ablation of lesions b. Treatment of lower GI bleeding c. Colonic decompression d. Dilation of colonic stenosis • Other indications a. Abnormal radiological examinations b. Isolated unexplained abdominal pain c. Chronic constipation d. Preoperative and intraoperative localization of colonic lesions