As with any procedure, there are risks associated with a colonoscopy. Before obtaining your consent for the procedure, the doctor will tell you about the potential risks.The most common side effects are cramping pain and abdominal swelling caused by the air used to inflate the colon during the procedure. This air is expelled shortly after the procedure, and these symptoms generally resolve without medical treatment.If a biopsy is performed during the procedure, the patient may see small amounts of blood in the bowel movements after the examination. This may last a few days.Though rare, there is potential for the colonoscope to injure the intestinal wall, causing perforation, infection, or bleeding.Although this test is very helpful in finding the cause of many digestive diseases, abnormalities can go undetected. Factors that can affect this include the completeness of the bowel preparation before the procedure, the skill of the operator of the colonoscope, and the patient's anatomy.When this test is performed, the patient will be given sedating medications to make the test more comfortable. Whenever a medication is given, a risk of an allergic reaction or side effect of the medication itself is present. These IV medications are given under medical supervision, and the patient will be monitored during the procedure to lessen the risk of medication-related complications.