Classification of purgatives

Purgative are drugs that induce defecation
They are divided into
Laxative & cathartics
Laxative: help in production of soft, formed stool
Cathartics: help in rapid, intense fluid evacuation of bowel
Ther are classified into following groups (BOSS)
B-Bulk forming e.g. methylcellulose, psyllium
O-Osmotic purgatives e.g. lactulose, magnesium salts
S-Stimulant e.g. castor oil, bisacodyl,
S- Surfactant e.g. bile acid, docusate salts