The bowel cleansing medicine is not defecated even after drinking it for 3 hours, which may be due to insufficient dosage of the medicine, poor sensitivity of the body, serious constipation, etc. According to the reasons, the dosage of the medicine can be increased, and enema can be taken to deal with the situation. 1. Insufficient drug dosage: when the dosage is too small, it will lead to slow onset of the drug effect, or even difficult to play a role in the effect, you should inform the physician and increase the dosage under the guidance of the physician as appropriate to achieve the desired effect of bowel cleansing, and do not increase or decrease the dosage at your own discretion. 2. Poor sensitivity of the body: some patients have poor sensitivity to a certain type or several kinds of drugs, so the effect of the drug is not good, generally can be taken to replace the other types of intestinal cleansing drugs to improve the effect of intestinal cleansing. 3. Serious constipation: avoid will lead to defecation difficulties, can be taken to soap and water enema, apply lubricant wearing gloves to gently pick out feces and other methods of treatment. Bowel cleansing medicine should be standardized under the guidance of a physician, not blindly self-medication. Bowel cleansing medicine drink 3 hours also do not defecate may have other reasons, you can go to the hospital to check to clarify the situation.