Side effects have been reported with ispaghula seed medicines, including flatulence and abdominal distension (swelling of the belly). There is a risk of a build-up of hard, dry stool, particularly if ispaghula seed is swallowed without enough liquid. Allergic reactions including rhinitis (runny nose), conjunctivitis (reddening and inflammation of the white of the eye), bronchospasm (excessive and prolonged contraction of the airway muscles) and anaphylaxis (severe allergic reaction) may also occur. When handling the powder preparation, inhalation of the powder should be avoided as this may lead to allergic sensitization and the potential development of allergies.

The HMPC recommended that ispaghula seed should not be used in patients with a sudden change in bowel habit that persists for more than two weeks, and in patients with undiagnosed bleeding of the rectum and failure to pass stools following the use of a laxative. It should also not be used in patients with conditions that involve a narrowing of the stomach and gut, and patients who have difficulty swallowing or have problems with their throat.

Further information on the risks associated with ispaghula seed medicines, including the appropriate precautions for their safe use, can be found in the monograph under the tab 'All documents'.