laxative
A laxative helps a stuck bowel move again, either by softening and bulking the stool so it slides more easily or by prompting the gut wall to push harder. It is a tool for constipation when diet, fluids and activity are not enough.
Laxatives fall into a few families by how they work. Bulk-forming agents (ispaghula, methylcellulose) absorb water and swell to increase stool mass and trigger stretch-driven movement. Osmotic agents (lactulose, macrogol, magnesium salts) hold water in the lumen to soften stool. Stimulant laxatives (senna, bisacodyl) directly increase intestinal motility and secretion. Stool softeners and lubricants ease passage. Newer agents act on specific channels or receptors to boost intestinal fluid.
Bulk-forming and osmotic laxatives are generally preferred for ongoing use; stimulants are best for short courses. Overuse can cause cramping, dehydration and electrolyte loss, and long-standing dependence is a real concern. Bulk agents need adequate water intake, and any new constipation with warning features deserves assessment rather than blind self-treatment.
An older patient on opioid painkillers, who has become constipated, is given macrogol to draw water into the bowel and soften the stool.
Macrogol is an osmotic laxative that retains water in the lumen to ease passage.
Stimulant laxatives suit short-term relief; for chronic constipation, bulk-forming and osmotic agents are usually safer first choices alongside diet and fluids.