Archive · 5 Sep 2026
Fibre Supplements May Cause Bloating, Gas and Diarrhoea
Fibre helps food move through the digestive system and supports gut health.
Some people use fibre supplements instead of getting fibre from foods.
Taking too much too quickly can cause bloating, gas or diarrhoea.
Drinking enough water is important because fibre absorbs water in the intestines.
Soluble fibre turns gel-like in water and may help with cholesterol and blood sugar.
Insoluble fibre adds bulk and helps waste move along.
People with sensitive guts may find some insoluble fibre uncomfortable.
A dietitian recommends starting supplements with a small amount and getting more fibre from foods such as oats, fruits, vegetables, beans, nuts and seeds.
Excessive fibre supplementation can cause bloating, gas and diarrhoea, especially when increased too quickly.
Insufficient fluid intake may worsen side effects because fibre absorbs water and adds bulk in the intestines.
Soluble fibre includes psyllium husk, guar gum, oat beta-glucan and chicory-root inulin.
Insoluble fibre supports regular bowel movements but may irritate sensitive guts or people with irritable bowel syndrome.
Adults generally need 25–30 grams of fibre daily, and supplements should be introduced gradually.
- Who
- People taking fibre supplements, with guidance from Deepalakshmi, a registered dietitian at Shree Balaji Medical Centre in Chennai.
- What
- The article explains how incorrect or excessive use of fibre supplements may cause bloating, gas and diarrhoea, and offers guidance on safer use.
- Where
- The dietary advice was provided by a registered dietitian at Shree Balaji Medical Centre, Chennai.
- Why
- Side effects may occur when fibre is increased too quickly, taken in excessive amounts or consumed with too little fluid.
- General adult fibre guideline
- About 25–30 grams per day.
- Suggested starting supplement dose
- Some supplements can be started at 2–3 grams per day and increased gradually.
- Suggested fluid intake
- The dietitian advises aiming for 8–10 glasses of water daily when taking supplements.
- Soluble fibre examples
- Psyllium husk, guar gum, oat beta-glucan and chicory-root inulin.
- Insoluble fibre examples
- Wheat bran, corn fibre and cellulose.
- Medication interactions
- Fibre may affect absorption of medicines including metformin, levothyroxine, statins and some antidepressants.
- Medication timing
- The dietitian recommends taking fibre supplements at least two hours before or after medicines.