Phenolphthalein tablets will be effective after 1-6 hours of administration, Phenolphthalein tablets have the effect of promoting intestinal peristalsis and softening feces, and are mainly used for the treatment of persistent constipation. People with constipation can use Phenolphthalein tablets to help improve the phenomenon of difficult stool discharge. After taking Phenolphthalein tablets for about an hour the peristaltic rate of the stomach and intestines will gradually increase, and at this time can be heard in the intestinal system will appear gurgling sound. Most people are able to pass stools after taking the drug for about 6 hours. As Phenolphthalein tablets can have an effect on the intestinal tract when taken for a long period of time, long-term use of the medication should be avoided, and it is best to take the medication once in a while. For people with constipation phenomenon usually should often massage the abdomen, appropriate exercise after meals can promote intestinal peristalsis, can help fecal discharge.