Causes and Diagnosis of Irritable bowel syndrome, London

Is food allergy a factor in Irritable bowel syndrome?

Many patients ask about food allergy, for obvious reasons. In fact, true food allergy is rare (an allergic reaction is generally an acute reaction to a specific food such an peanut or seafood allergy. Most patients (in fact nearly all) with IBS do not have a food allergy. Food intolerance, on the other hand, is more common but difficult to define. The gut is there for food and therefore, by definition, meal related symptoms are a food intolerance. Specific food intolerances are common in IBS. Milk (lactose) intolerance is often present in post-infective IBS but less often in other cases. Wheat intolerance is much talked about and is certainly a common problem in IBS. The main problem with wheat relates to excessive fermentation (not an allergy) and the main symptom is therefore bloating.

Bloating and Fermentation in Irritable bowel syndrome

Bloating is one of the commonest presenting symptoms in IBS, particularly in women. Bloating is caused by excessive intestinal gas production. In a few cases, especially those who eat fast, belch and bloat very quickly, swallowing of air is the problem. This is usually obvious to the doctor although not well recognised. Most bloating, however, comes from gas production lower down the gut at the end of the small intestine and, in particular, in the colon. Here there are huge numbers of bacteria, some of which are expert at fermenting plant fibres into gas (including hydrogen, methane, carbon dioxide and hydrogen sulphide). Constipation often accompanies bloating – stool is composed mainly of bacteria so slow passage of stool around a long colon is going to be a perfect recipe for fermentation and therefore bloating and gas. Diets which reduce this are those that reduce wheat and insoluble fibres and fermentable vegetables such as broccoli, greens and beans (pulses). These are, of course, the very foods that we are persuaded to eat in a healthy diet so advice to remove them comes as a surprise. It is, however, often very successful.

Is Candida a real problem in Irritable bowel syndrome?

The answer to this is almost certainly yes. It is controversial and overstated but there is clearly a group of women (sometimes men too) who have a tendancy to genital candida (thrush) and have bloating, sometimes diarrhoea but may be constipation, and often have fatigue and general symptoms. Foods containing yeast make the symptoms worse, such as bread, marmite, wine and beer (but not spiritis) and sugar will also do the same as it promotes yeast driven fermentation. There is no proof of an overgrowth of candida (or other yeasts) in the gut but it makes sense and diets avoiding yeast and sugar can help (they are also very difficult as avoiding sugar leads to excessive tiredness). Antifungal drugs can also help, usually temporarily.


How do I get treatment?

To get further information or treatment, please contact one of our consultants at The London Bridge Digestion centre, on:

tel: +44 (0) 20 7403 3814