Laxative is a medicine that speeds the emptying of the bowels (intestines). Mineral oil is a laxative that helps empty the bowels by lubricating the bowel contents. Phenolphthalein, the active ingredient in chewable and chocolate laxatives, has a direct effect on the intestine, but how it works is not clear. Some laxatives, including Epsom salt, provide bulk in the form of retained water. The water increases the bowel contents and forces the bowels to empty. Other laxatives, including castor oil, act by irritating the walls of the bowels.
Laxatives should not be taken continually over a long period of time because the bowels may become lazy and fail to function on their own. Laxatives may also cause harmful side effects in other parts of the body. They should never be taken by people who have abdominal pain. Constipation (difficulty in emptying the bowels) can often be relieved by drinking ample quantities of water and by eating foods containing fiber. These foods include cereals, whole fruits, and leafy vegetables.
