About Fybogel (ispaghula husk)Ispaghula husk is a laxative taken to treat?constipation?(difficulty pooing). It’s usually known by the brand name Fybogel. Other brand names include Ispagel.It works by bulking poo up with fluid so that it’s softer.It comes as plain or fruit-flavoured granules that you mix with water to make a high-fibre drink.Fybogel is available on prescription and to buy from pharmacies and supermarkets.Key factsFybogel is a high-fibre drink that you take in the morning and evening, preferably after a meal.It usually takes 2 or 3 days to work.When taking this type of laxative, it’s important to drink plenty of fluids.The main side effects are wind and bloating.It’s possible to have a mild allergic reaction to Fybogel such as itchy eyes, nose or skin.