Laxativ

Laxativ, or laxative, is a medication or substance that accelerates bowel movements to relieve constipation. They work by altering stool consistency or stimulating intestinal activity and are used when dietary measures fail or when rapid bowel evacuation is needed, such as before medical procedures.

Most laxatives are grouped by mechanism: bulk-forming agents (psyllium, methylcellulose) draw water into the stool to soften and increase volume; osmotic laxatives (polyethylene glycol, lactulose, magnesium salts) hold water in the bowel to soften stool and promote peristalsis; stimulant laxatives (bisacodyl, senna) trigger intestinal contractions; stool softeners (docusate) reduce stool surface tension to aid water entry. There are combination products and saline laxatives as well. Onset varies: bulk-forming 12–72 hours, osmotic several hours to a day or more, stimulant: oral 6–12 hours; rectal 15–60 minutes, stool softeners 12–72 hours.

Indications include occasional constipation, preparation for medical examinations, and to prevent straining in patients with conditions where increased abdominal pressure is undesirable. They are generally intended for short-term use and should be used with adequate hydration and dietary fiber. Chronic or excessive use, especially of stimulant laxatives, can lead to electrolyte disturbances, dehydration, and dependence.

Contraindications include intestinal obstruction, undiagnosed abdominal pain, inflammatory bowel disease with risk of perforation, and severe dehydration. Side effects can include bloating, gas, cramping, and diarrhea; interactions with other medicines can occur due to altered absorption or electrolyte balance. Availability is often over the counter, with stronger formulations available by prescription for specific indications.