Laxative

From WikiMD's Wellness Encyclopedia

(Redirected from Stimulant laxative)

Laxatives are medicinal substances designed to stimulate defecation and relieve constipation. This pharmacological group may also be utilized in the preparation of rectal and bowel examinations by cleansing the colon. While most commonly used to address constipation, laxatives may be misused, especially among individuals suffering from eating disorders such as bulimia nervosa and anorexia nervosa. Laxative misuse can result in serious health complications, including intestinal paralysis, irritable bowel syndrome (IBS), and pancreatitis.

Laxatives
Glycerin suppositories

Laxatives may be administered orally or in suppository form. They can be classified into several categories based on their mode of action and site of action in the digestive tract. It's important to note that while constipation affects all sexes equally, some laxative brands may be marketed with a particular gender focus.

Bulk-forming Laxatives[edit | edit source]

Acting in both the small and large intestine, bulk-forming laxatives function by increasing fecal bulk and water content, facilitating peristaltic movement. This category includes dietary fibers such as psyllium husk, methylcellulose, and polycarbophil. These are typically the gentlest laxatives and can be used to maintain regular bowel movements.

Stool Softeners and Surfactants[edit | edit source]

Stool softeners operate in the small and large intestines by enabling water and fats to infiltrate the stool, thus easing its passage. Extended use can result in tolerance and reduced effectiveness. Examples include docusate sodium.

Lubricants[edit | edit source]

Lubricants like mineral oil facilitate the passage of stool through the colon by making it slippery. This category also impedes colonic absorption of water, further softening the stool. It's important to note that mineral oil can inhibit the absorption of fat-soluble vitamins.

Hydrating Agents (Osmotics)[edit | edit source]

Osmotic laxatives function by increasing water concentration in the intestines, which softens the stool. Saline and hyperosmotic are the two principal types.

Saline Laxatives[edit | edit source]

These work by attracting and retaining water in the intestinal lumen, stimulating the release of cholecystokinin, which aids in the digestion of fats and proteins. Notable examples include sodium phosphate, magnesium hydroxide (Milk of magnesia), and magnesium sulfate.

Hyperosmotic Agents[edit | edit source]

Hyperosmotic laxatives like glycerin suppositories and lactulose work primarily by increasing the osmotic effect within the colon, facilitating the retention of water.

Stimulant Laxatives[edit | edit source]

These agents stimulate peristaltic action in the colon and modify water and electrolyte secretion. Examples include bisacodyl, senna, and castor oil, which are typically reserved for more severe cases of constipation due to their powerful effects.

Laxative Resources




Contributors: Prab R. Tumpati, MD