A vegetarian diet could help protect against a common bowel disorder, research has suggested.

Vegetarians were found to be a third less likely to get diverticular disease, a condition thought to be caused by eating too little fibre. It causes cramps, bloating, wind,constipation and diarrhoea.

A study led by Francesca Crowe from the Cancer Epidemiology Unit at Oxford University, published online by the British Medical Journal, looked at 47,033 British adults, of whom 15,459 were vegetarian.

After an average follow-up of 11.6 years, there were 812 cases of diverticular disease. Vegetarians in the group had a 30 per cent lower risk of having the disease, compared to those who ate meat, fish or both.

The authors said the reason could be the consumption of meat altering the metabolism of bacteria in the colon, and therefore weakening the colon wall and increasing the risk of diverticular disease.

They found nothing significant about the amount of meat eaten.

The potential protective benefits of vegetarianism could be obtained even in a short time, the study found.

There also seemed to be a link between eating more fibre and being at lower risk of the disease.

Patients who consumed the most fibre, more than 25.5g per day for women and more than 26.1 g for men, had a 42 per cent lower risk than those who ate less than 14 g per day.