A purgative is a substance that strongly stimulates bowel evacuation, the stronger-acting end of the laxative family. Purgatives work by irritating the intestinal lining, drawing water into the bowel, or triggering powerful muscular contractions, producing a rapid and thorough clear-out. Traditional examples include castor oil and senna, while modern medicine uses potent osmotic agents to empty the bowel before surgery or colonoscopy. Because their action is forceful, purgatives can cause cramping, dehydration, and dangerous electrolyte disturbance, especially with repeated use, and chronic misuse for weight control is a recognised form of disordered eating. They have legitimate clinical roles but are unsuitable for routine constipation, where gentler bulk-forming or osmotic laxatives are preferred.