Background: colonoscopy is the “gold standard” for diagnosis of colonic mucosal disease. Colonoscopy has greater sensitivity than barium enema or CT for colitis, polyps, and cancer Colonoscopy has the advantage of not only picking up primary cancer but also having the ability to detect synchronous polyps or even multiple carcinomas, which occur in 5% of cases. It tends to be used in patients whose main presenting symptom is bleeding, those with known polyps and those in whom there is doubtful radiology. Ideally, every case should be proven histologically before surgery. Aims: To establish a correlation between clinical diagnosis, colonoscopy and histological findings of colon lesions. Materials and Methods: The study was done at Department of Pathology, MGMCH, Jaipur it was a Hospital-based observational study consisting of 60 cases. The findings of clinical diagnosis, colonoscopy and histology were correlated. Statistical methods: sensitivity, positive predictive value, negative predictive value, and specificity was calculated Results: Among 60 cases, 41 cases were Nonneoplastic, 15 cases were Neoplastic and 4 cases were classified as biopsy specimen inadequate or unsatisfactory for evaluation. In our study, colonoscopy with biopsy was performed on patients of all age groups, ranging from 2 years to 87 years. Conclusion: Colonoscopy is a safe procedure and has a high diagnostic yield. The endoscopic evaluation of the large bowel has been greatly expanded by the availability of colonoscopy.A comprehensive histopathological study of the colonoscopy biopsy specimens should be done in constant correlation with the clinical and colonoscopy features.

Keywords: Colonoscopy; Histopathology; Clinical Diagnosis; Polyps; Adenocarcinoma.