Background and study aim: Colonoscopy is recommended by many international gastroenterology and cancer societies as the initial diagnostic modality for colorectal cancer. It is considered the most accurate diagnostic tool in inflammatory bowel disease. These are two identified subtypes of the disease, ulcerative colitis (UC) and Crohn's disease. The previous studies on Egyptian patients said that the incidence of IBD increased significantly in the past ten years. The aim of this study was to calculate the prevalence of IBD among patients referred to endoscopy units to perform colonoscopy and define the most common presenting symptoms of IBD. We also wanted to shed light on the most common presenting complaints that lead to referral to colonoscopy and the common colonic lesions that were diagnosed by colonoscopy.r Patients and Methods: Cross sectional study involved 250 patients who underwent colonoscopy in the period from November 2014 to November 2015, the presenting complaint was recorded as well as the results of colonoscopy. Results: Bleeding per rectum was the commonest indication for colonoscopy (46%) followed by chronic abdominal pain (20%), then chronic diarrhea (17%). The commonest pathological conditions were internal hemorrhoids in 27.6% followed by nonspecific colitis in 20.4%, ulcerative colitis in 10.4%, carcinoma in 10.4%, Crohn's in 0.8% then polyps in 0.4%. UC/CD ratio was 13:1. Conclusion: In a group of Egyptian patients undergoing colonoscopy the most frequent diagnosis were internal piles, non-specific colitis followed by inflammatory bowel disease with a prevalence of 11.2% and predominance of UC over CD.