The diagnostic opinion of colonoscopy without biopsy is generally accurate. When performing colonoscopy, when the operating physician holds doubts about the lesion or found to have obvious malignant lesions, it is necessary to take a biopsy and wait for the return of pathological results to clarify the type of pathology, the diagnosis on the report of the colonoscopy at this time is generally correct, just not sure whether the pathological results of the results of good or bad results, it is inconvenient to formulate a treatment plan. Do not take a biopsy of the situation in addition to the line of colonoscopy did not find obvious malignant lesions, there is also when the patient line of examination, has been in the oral antiplatelet drugs (such as aspirin) has not been stopped for 3 to 7 days, this time to take a biopsy of the risk of bleeding, generally will not be taken. If a problem is found at this time, the colonoscopy can be repeated and a biopsy taken after the medication has been stopped. Generally speaking, the doctor will decide whether to take a biopsy or not based on his/her professional knowledge and experience, and then carefully write a report and give it to the patient, so the diagnosis is generally accurate.