A second colonoscopy with half the vomiting from the medication may be effective. If the nausea and vomiting caused by drinking bowel cleansing medication is not excessive and the bowel movements are clear or yellowish watery, the colonoscopy may be continued. If the vomiting is excessive and the bowel movements are not clean, colonoscopy should not be performed. The prerequisite for colonoscopy is bowel preparation, i.e., bowel cleansing, usually taking laxatives one day before the examination, which can be compounded with polyethylene glycol powder, and with appropriate exercise, which can effectively promote intestinal peristalsis, and should be excreted as much as possible. Usually, the colonoscopy can only be carried out after the patient has excreted to clear water-like stool. Some patients have nausea and vomiting after taking bowel cleansing medication, which can be achieved by slowing down the speed of taking the medication, adding light-colored fruit juice into the laxative, and encouragement from family members, etc. This can help the patients take the medication to a certain extent, so as to achieve satisfactory bowel cleansing effect. If the patient is still unable to cooperate, enema can be chosen to clean the intestines before performing colonoscopy. Please take the medicine under the guidance of the doctor, not blindly self-medication to avoid adverse effects.