Most facilities require that patients have a person with them to help them home afterwards (depending on the sedation method used). One common after-effect from the procedure is a bout of flatulence and minor wind pain caused by air insufflation into the colon during the procedure. An advantage of colonoscopy over X-ray imaging or other less invasive tests is the ability to perform therapeutic interventions during the test. A polyp is a growth of excess of tissue that can develop into cancer. If a polyp is found, for example, it can be removed by one of several techniques. A snare device can be placed around a polyp for removal. Even if the polyp is flat on the surface it can often be removed. For example, the following shows a polyp removed in stages:

Pain management
The pain associated with the procedure is not caused by the insertion of the scope but rather by the inflation of the colon in order to do the inspection. The scope itself is essentially a long, flexible tube about a centimeter in diameter — that is, as big around as the little finger, which is less than the diameter of an average stool. The colon is wrinkled and corrugated, somewhat like an accordion or a clothes-dryer exhaust tube, which gives it the large surface area needed for water absorption.
Research shows that the risk of cancer is low for 10 years if a high-quality colonoscopy does not detect cancer, so tests for this purpose are indicated every ten years.Colonoscopy screening prevents approximately two-thirds of deaths due to colorectal cancers on the left side of the colon, and is not associated with a significant reduction in deaths from right-sided disease.Colonoscopy reduces cancer rates by detecting some colon polyps and cancers on the left side of the colon early enough that they may be treated, and a smaller number on the right side; many of these left-sided growths would have been detected by a sigmoidoscopy procedure.Since polyps often take 10 to 15 years to transform into cancer in someone at average risk of colorectal cancer, guidelines recommend 10 years after a normal screening colonoscopy before the next colonoscopy. (This interval does not apply to people at high risk of colorectal cancer, or to those who experience symptoms of colorectal cancer. )Although widely touted in the US as the "gold standard" of colon cancer screening, colonoscopy has never been studied as a screening tool. Most of the potential benefits of colonoscopy have been extrapolated from randomized trials of the sigmoidoscopy. The CONFIRM trial, a randomized trial on colonoscopy vs. FIT is currently ongoing.