Colonoscopies are often painful, although the patient receives sedation during the procedure, reports WebMD. Patients generally feel cramping and brief, sharp pains as the scope used for the procedure moves around the colon or from air blown into the colon during the exam.
During the procedure, many people feel the need to have bowel movements or pass gas, notes WebMD. The sedation causes sleepiness and relaxation. After the test, many people feel bloated or have cramps and gas pains. If the doctor collects a biopsy or takes out a polyp, traces of blood may appear in the stool in the days following the exam.