Phenolphthalein tablets are mainly used for the treatment of stubborn and habitual constipation, usually 4-8 hours after the use of phenolphthalein tablets patients can discharge soft stool. Phenolphthalein tablets are mainly used for the treatment of constipation in the clinic, mainly in the colon, after oral administration in the small intestine under the action of alkaline intestinal fluid can be slowly decomposed, the formation of soluble sodium salts, thus stimulating the intestinal wall, nerve plexus, direct action on the smooth muscle of the intestine, so that intestinal peristalsis increased, and at the same time can inhibit the absorption of water in the intestinal tract, so that the water and electrolytes in the colon to produce the effect of retarded diarrhea accumulation. Phenolphthalein tablets orally about 15% is absorbed, the absorbed drug is mainly in the form of glucuronide, with urine or fecal excretion, part of the drug can also be excreted through the bile to the intestinal lumen, in the intestinal reabsorption, the formation of hepatic and intestinal circulation, can prolong the action of the drug time, so a dose of the drug needs 3-4 days after the body can be completely eliminated. In conclusion, Phenolphthalein tablets for the treatment of stubborn or habitual constipation, the therapeutic effect can be seen in 4-8 hours after the administration of the drug, and soft stools can be discharged. Phenolphthalein tablets for the treatment of stubborn and habitual constipation, can not be taken for a long time, long-term application can cause dependence on the drug, but also can make the blood glucose increase, blood potassium decrease. This product should be used with caution for pregnant women and young children, and should be contraindicated for lactating women and infants.