Stimulant laxatives work by irritating the lining of the intestines. This in turn irritates the nerves that cause the intestinal muscles to move, resulting in a bowel movement.

Laxatives should not be used in anyone who has abdominal pain, nausea, or vomiting. They should not be used for longer than one week of regular treatment.

The ingredient most commonly used in stimulant laxatives is bisacodyl (Dulcolax, Correctol). This form is available in tablets and suppository form. The tablets usually work in six to ten hours. The rectal suppositories work in 15 to 60 minutes.
Phenolphthalein is another stimulant ingredient found in Ex-Lax, Feen-A-Mint Gum, Modane and Alophen. This stimulant usually works in six to eight hours. Aloe, cascara, and senna are stimulants that usually work in eight to twelve hours.