Stool softeners work by softening and preventing dryness of stool without stimulating the bowel. Mineral oil works by softening and lubricating the stool to allow for easier passage. Gycerine suppositories can lubricate and ease the passage of dry, hardened stool. Magnesium salts like Phillips Milk of Magnesia and epsom salts work by drawing fluid out of the bowel into the stool. A loose watery stool is the usual result.
Enemas act by filling the bowel which stimulates the urge to have a bowel movement.
Bowel stimulants such as Ex-Lax, Correctol, castor oil and Dulcolax cause the contents of the bowel to move along more quickly. As a result, less fluid is absorbed from the stool and it passes more easily. In general, it is best to try the gentler agents first. Prolonged use of medications or products to promote regularity may result in dependence on them. If the need for a laxative exceeds 3 to 5 days, contact your doctor or appropriate health care provider.