Bulk-forming laxative
- Non-absorbable fiber absorbs water → increases stool bulk
- Bulk stretches the colon wall → stimulates peristalsis
- Requires adequate water; otherwise the added bulk can obstruct
- Adds stool bulk and draws water into the lumen
- Requires water to work; without it the bulk can obstruct
- ⚑ Avoid with clozapine — additive risk of bowel obstruction
Drugs with this mechanism (6)
- Acacia gum — Soluble prebiotic fiber used in dietary supplements; also a pharmaceutical thickener and stabilizer.
- Calcium polycarbophil — Nonfermentable bulk-forming fiber that can normalize either hard or loose stool.
- Inulin — Fermentable prebiotic fiber that can improve bowel regularity; gas and bloating commonly limit tolerance.
- Methylcellulose — Nonfermentable bulk-forming fiber for constipation; usually causes less gas than psyllium.
- Psyllium — Soluble fiber; needs fluid or it obstructs.
- Wheat dextrin — Soluble fiber supplement; fermentation can cause gas and bloating.
All mechanisms · Open Bulk-forming laxative in the interactive console ↗