How does it work?

Mesalazine is an anti‑inflammatory medicine used in inflammatory bowel disease (IBD), including ulcerative colitis. It works mainly in the lining of the bowel, where it helps reduce inflammation. The exact mechanism is not fully understood, but it is described as acting locally in the gut.

How do I take it?

Mesalazine is available in several forms, including tablets, granules, suppositories and enemas, and the dose and schedule depend on the product and the reason it has been prescribed. Some people take Mesalazine once daily, while others may take it in divided doses.⁷ Tablets are generally swallowed whole with water and should not be broken, chewed or crushed, as some have a special coating. Always follow the instructions from your prescriber, pharmacist, and the Patient Information Leaflet (PIL) supplied with your medicine.

Possible side effects

Like all medicines, Mesalazine can cause side effects, although many people have none or only minor effects. Reported common side effects include indigestion or wind, stomach pain, nausea or vomiting, diarrhoea, and headaches. Serious side effects are uncommon, but the NHS advises seeking medical advice for certain symptoms, including significant skin reactions, and notes monitoring for kidney function during treatment.

Important advice

Do not stop taking Mesalazine unless your doctor tells you to, as symptoms may return. Read the Patient Information Leaflet (PIL) supplied with your medicine and attend any monitoring appointments arranged by your healthcare professional (including checks of kidney function where recommended).If you experience side effects that concern you, or symptoms that worsen, seek medical advice. Suspected side effects can also be reported via the MHRA Yellow Card scheme.