Laxatives (
purgatives,
aperients) are substances that loosen
stools and increase
bowel movements. They are used to treat and prevent
constipation. Laxatives vary based on how they work and the side effects they have. Certain
stimulant,
lubricant and
saline laxatives are used to evacuate the
colon for
rectal and bowel examinations, and may be supplemented by
enemas under certain circumstances. Sufficiently high doses of laxatives may cause
diarrhea.