Researchers at St George's Hospital have discovered drugs which help ease the effects of Crohn's disease.

The drugs, known as Thiopurines, dramatically reduce the need for surgery when treating the disease, also known as Inflammatory Bowel Disease (IBD).

A study of 12,000 patients found long-term use of the medication noticeably reduced inflammation of the gut, resulting in a 40 per cent reduction in the need for bowel surgery.

Researchers, made up of a team from St George's Hospital Tooting, St James Hospital Leeds and Imperial College London, used data stretching back more than a decade.

Thiopurines are already used to treat IBD, but nobody realised before how significant their impact was over an extended period of time.

Dr Richard Pollok, lead author, said: "We now know that there is a clear benefit in persisting with an alternative treatment that will help patients remain symptom free and also decrease their chances of having to be admitted to hospital for major surgery to remove their bowel.

"We recommend this treatment in patients with clinical symptoms and blood tests that suggest they are likely to require bowel surgery."

IBD affects more than a quarter of a million people in the UK.