A laxative is a preparation used for the purpose of encouraging defecation, or the elimination of feces. Laxatives are most often taken in response to constipation. They are also sometimes used before medical procedures. They are often abused by bulimics or anorexics. Laxatives are sometimes supplemented by enemas.

Laxative abuse is a problem that is potentially very serious. Laxative abuse can lead to problems such as intestinal paralysis.

Laxatives are of several types, listed below. A type not listed is the combination laxative, which simply means that the laxative has more than one ingredient, with a combination of effects. Laxatives may be oral or in suppository form.

It is interesting to note, that while there is no gender based medicine to ease constipation, advertisers tend to promote some brands as being "More for a lady" than others

Bulking agents (fiber)

These include dietary fiber. Bulking agents cause the stool to be bulkier and to retain more water, making it easier for peristaltic action to move it along. Examples: Metamucil, psyllium seed, apples

Stool softeners

These cause water and fats to penetrate the stool, making it easier to move along. Many of these quickly produce a tolerance effect and so become ineffective with prolonged use. Example: Doxidan

Hydrating agents (osmotics)

These cause the intestines to concentrate more water within, softening the stool. There are two principal types, saline and lactulose. Examples: Milk of Magnesia, Epsom salt, Magnesium citrate .

Lubricants

These simply make the stool more slippery, so that it slides through the intestine easier. Example: mineral oil

Stimulants (cathartics)

These stimulate peristaltic action, and can be dangerous under certain circumstances. Examples: Ex-Lax, Feen-a-Mint, senna, cascara, bisacodyl .