What’s the deal with breath tests?

Do you need a breath test to diagnose IBS?

Breath testing is no longer recommended for most people with IBS as first line investigation. Breath testing can be used to give an indication of whether you have an intolerance to sugars like lactose, fructose, sorbitol, sucrose and mannitol. The issue is that the results of the breath test don’t always align with what your body can actually tolerate in IBS. Many people have a positive breath test showing ‘intolerance’ to one of these sugars but they still may tolerate having a modest amount in their diet. It is much more useful to try a FODMAPs elimination diet where these sugars are removed from the diet and then use a re-challenge protocol (with an experienced dietician) as this will give you much more practical answers as to what your body can tolerate. The tests can also be quite expensive and take a lot of time and energy to complete as only a single sugar can be tested on a breath test at one time and requires some prep work too. Of course, every case is different and in certain circumstances your GP/dietician may recommend breath tests as an adjunct to your management plan.