Laxatives How do they work?

May 8, 2026

Upload by Patrick

Laxatives are medications used to treat constipation by facilitating bowel movements. There are various types of laxatives, each with a specific mechanism of action. Stimulant, emollient, and saline laxatives are employed to clear the colon for rectal and bowel examinations. Stool softeners or mineral oil are recommended for preventing straining during defecation, particularly after anorectal surgery or myocardial infarction. Psyllium and polycarbophil are beneficial for managing irritable bowel syndrome and diverticular disease. Hyperosmotic agents, such as lactulose, are used to reduce blood ammonia levels in cases of hepatic encephalopathy. Common reasons for laxative use include constipation and sometimes diarrhea when a loss of water and electrolytes is a concern. Potential side effects of laxatives are diverse and can include abdominal pain or discomfort, nausea, vomiting, perianal irritation, fainting, bloating, flatulence, cramps, and weakness. Prolonged or excessive use can lead to serious electrolyte imbalances and the development of a dependency, known as the "laxative habit." Some laxative products contain tartrazine, a yellow food dye that may trigger allergic reactions, including asthma, in susceptible individuals. Bulk-forming laxatives, if taken without adequate fluid intake or in patients with intestinal stenosis, can cause obstruction in the esophagus, stomach, small intestine, or colon. Interactions with other medications are also a critical consideration. Mineral oil can hinder the absorption of fat-soluble vitamins (A, D, E, and K). Laxatives, in general, may reduce the absorption of other drugs in the gastrointestinal tract by either chemical binding or by accelerating their passage. A specific interaction occurs when surfactants are administered with mineral oil, as they can increase the absorption of mineral oil. Furthermore, milk, antacids, histamine H2 antagonists, and proton pump inhibitors should not be taken within 1 to 2 hours of bisacodyl tablets, as this can lead to premature dissolution of the enteric coating, causing gastric irritation and reducing the drug's efficacy.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages1

Reading Time3 min

AccessFree to download

May 8, 2026

Upload by Patrick