The time of defecation after drinking castor oil is related to the individual’s constitution, generally about 30 minutes to 3 hours to defecate, depending on the individual. Castor oil has a laxative effect and is often used in the treatment of intestinal dryness and constipation. Castor oil is taken orally to the small intestine, where it is hydrolyzed by lipase hydrolase, releasing sodium ricinoleate, which stimulates the wall of the small intestine and promotes defecation. After taking castor oil orally, at least 2000ml of warm water should be taken orally again, and defecation can usually occur in about 30 minutes for those who are sensitive, and in about 3 hours for those who are slow to respond. If there is still no obvious defecation in 3 hours, you can walk more to speed up intestinal peristalsis and promote defecation. However, it is not recommended to take castor oil frequently for defecation to prevent intestinal dependence and even easy to develop colon melanosis. Before taking laxatives, note that other serious intestinal diseases such as intestinal obstruction must be ruled out first. It is usually recommended to drink more water, eat more vegetables and fruits, and develop good bowel habits.