Screening and Prevalence of Internal Hemorrhoids in Patients Undergoing Flexible Colonoscopy Background: Hemorrhoids are swollen veins of the hemorrhoidal plexus that are normally present in the anal canal. Clinically detectable if the supporting connective tissue is compromised. In this study, we focused on the effectiveness and importance of Colonoscopy to the study of the prevalence of internal hemorrhoids Objective: The study aimed to evaluate the Prevalence of internal hemorrhoids in patients undergoing colonoscopy for different indication Patients and Methods: This cross-sectional study was conducted in the elective gastrointestinal endoscopy unit, Internal Medicine Department, Faculty of Medicine, Zagazig University from March 2021 to August 2021, and including 300 consecutive Egyptian patients who underwent a flexible colonoscopy were enrolled in this study for different reasons Results: In the present study, we revealed that hemorrhoids increasing with aging (p<5). The diagnostic results were internal hemorrhoids (38.3%), colonic ulcers (11%) inflammatory lesions (7.3%) and Mass (7%), diverticular disease (6%), polyps (5.7%), and vascular malformations (1.3%) The complaints of the patients were lower GI bleeding (41.7%). Chronic diarrhea (17.7%) abdominal pain (14.7%), and chronic constipation (13.3%) were in the subsequent levels. Also chronic anemia (6.7%), follow-up colon polyp (5.3%), one (0.3%) patient had weight loss and one (0.3%) patient had anal pain Conclusions: We can conclude a wide prevalence of internal hemorrhoids in patients who underwent colonoscopy for various reasons. Besides, retroflexed colonoscopy can contribute to the study of the prevalence of internal hemorrhoids because it can diagnose even asymptomatic hemorrhoids. In addition, colonoscopy was found to be extremely safe and no complication was detected.