Gluten-Free Alternative to Wheat Bran for Constipation
For patients avoiding gluten who need a fiber supplement for constipation, psyllium husk (ispaghula) is the recommended alternative to wheat bran, starting at 3-4 g/day and gradually increasing to 10-11 g/day divided into two doses, taken with at least 240-300 mL of water per dose. 1, 2
Why Psyllium is the Preferred Alternative
Psyllium is the only fiber supplement with solid evidence of efficacy for chronic constipation, demonstrating a significant increase in weekly bowel movements (mean difference: 2.32 bowel movements per week) and improved global symptom relief compared to placebo. 1, 2 The American Gastroenterological Association and American College of Gastroenterology specifically recommend psyllium as having the strongest evidence base among fiber supplements. 1
Key Advantages Over Wheat Bran
Better tolerability: Psyllium causes less abdominal distension and bloating compared to wheat bran, which frequently worsens these symptoms and leads to treatment discontinuation. 1, 3
Superior efficacy: In head-to-head comparisons, psyllium was 3.4 times more effective than wheat bran for increasing stool output in patients with chronic constipation. 4
Naturally gluten-free: Psyllium is derived from plantago seed husks and contains no gluten, making it safe for patients with celiac disease or gluten sensitivity. 3
Dosing Protocol
Start low and titrate slowly to minimize gas and bloating:
- Initial dose: 3-4 g/day (approximately one teaspoon) 1
- Target dose: 10-11 g/day, divided into two doses of 5 g each, taken before meals 1, 2
- Titration: Gradually increase over 2-4 weeks to reach target dose 1
- Fluid requirement: Each dose must be taken with at least 240-300 mL (8-10 ounces) of water to prevent intestinal obstruction 1, 2
Critical Safety Considerations
Adequate hydration is non-negotiable when using psyllium:
Risk of intestinal obstruction: Psyllium can cause serious intestinal obstruction if not taken with sufficient fluid, particularly in elderly patients or with prolonged use. 2
Contraindications: Do not use in non-ambulatory patients or those with inadequate fluid intake. 5, 2
Opioid-induced constipation: Avoid psyllium in patients taking opioids, as it may worsen symptoms; use osmotic or stimulant laxatives instead. 2
Expected Timeline and Treatment Escalation
Minimum trial duration: At least 4 weeks of treatment at target dose is needed to assess efficacy. 2
Common side effects: Flatulence, mild abdominal distension, and bloating are expected but generally do not require discontinuation. 1, 2
If inadequate response: After 4 weeks at target dose, escalate to osmotic laxatives (polyethylene glycol) or stimulant laxatives rather than increasing psyllium dose further. 2
What NOT to Use
Avoid these alternatives:
Insoluble fibers (including wheat bran substitutes like rice bran or corn bran): May exacerbate symptoms and worsen abdominal pain. 1
Guar gum: Not recommended by guidelines, with no significant effect on bowel movement frequency when added to high-fiber diet. 2
Inulin: Does not increase stool weight to the extent that psyllium does, though it has prebiotic properties. 1