Colonoscopy procedure:Have you ever heard about Colonoscopy? Why is it done? Do you know what are the reasons ,why doctor might suggest you have a Colonoscopy and in which kind of diseases it is useful in ? A Colonoscopy is a procedure or a test that is used for diagnosis of certain harmful diseases of large intestine.Dr.Piyush Rajan, Gastroenterologist from Sir Ganga Ram hospital,New Delhi explains the reasons why Colonoscopy test is required and which are certain diseases that require the need for procedure of this test .According to Dr Piyush Rajan there are four main reasons for Colonoscopy(1) Presence