If a thin person chooses a painless colonoscopy when having a colonoscopy, there is usually no pain, but if they choose a normal colonoscopy, there may be some pain. Therefore, whether thin people have pain when doing colonoscopy needs to be judged according to the way of colonoscopy, and has no direct relationship with fat and thin. 1. No pain: for thin people who choose painless colonoscopy, anesthesia needs to be used before the examination, and no stimulation or other adverse reactions are felt during the examination. Therefore, it will not feel the pain. 2. Pain: if the thin people for colonoscopy, the choice of ordinary colonoscopy, in the inspection process will cause irritation to the intestinal mucosa, and then appear pain symptoms, so there will be pain. When you need to undergo colonoscopy, you should choose the appropriate examination method under the guidance of the doctor to reduce the pain.