Colonoscopy is the one of the most important investigation to be done for patients presenting with symptoms of colonic diseases. The clinical presentation of lower GI tract diseases varies in different communities. The yield of colonoscopy also varies from place to place and the yield also depends on the various indications.                                                                                        Aim of the Study: To know the indications for colonoscopy in patients with symptoms of lower GI tract diseases and also to assess the yield of colonoscopy in various indications. Materials and Methods: A retrospective study of patients who underwent colonoscopy from November 2014 to October 2016 at CMCH __ampersandsign RC was done. Data were collected from endoscopy register and analysed. Results: A total of 513 patients who registered for colonoscopy were evaluated. Male: female ratio was 341:172. Among those 506 patients (98.6%) tolerated the procedure. Caecum could be reached for 91.3% of the patients. Most common indication was bleeding per rectum 25.49%, clinical suspicion of Irritable Bowel Syndrome (IBS) 17.7%, Constipation 15.2%. The findings were normal study in 36.56%, haemorrhoids: 30.8%, polyp colon: 9.2%, Inflammatory Bowel Disease: 6.52%, carcinoma: 4.74%. Polypectomy was done in 10 cases. Overall yield of colonoscopy was 63.5%. Conclusion: Colonoscopy is an effective procedure for diagnosing lower GI symptoms. The yield of colonoscopy is high in patients with symptoms of bleeding per rectum, carcinoma colon, anaemia, Ileocaecal kochs..