An observational multi center study to find the rate of occurrence of polyps or cancers in large intestine and study of risk factors causing polys and cancer

Intervention1: Group A- Pt with Alarming symptoms: Symptomatic patients: with presence of alarm symptoms, history of inflammatory bowel disease, presence of active colitis or diverticulitis. These participant will undergo colonoscopy only once after enrollment. Control Intervention1: Group B Pt without alarming symptoms: Patients who are undergoing colonoscopy but not meeting the criteria of group A. These participant will undergo colonoscopy only once after enrollment. Primary outcome(s): prevalence of colorectal polyp and lower GI cancersTimepoint: 18 months after completion of the enrollment