Unfortunately there are no tests that provide information that gives you a clear diet direction in IBS. That is because there is no clear physiological mechanism known to be at fault in IBS. Diet options for IBS is still a new area for dietetics. It is rather like diet and migraine, another symptom where the problem physiological mechanism is not known. From my clinical research they are both symptoms that occur in food sensitive people. Another symptom is eczema which does have some allergic part. So allergy tests can be helpful with eczema though often not the full solution.
Thinking back over my clinical research I have only rarely had IBS patients who had an allergic reaction with their IBS. Where it occurs they often report, for example, that they are allergic to some food that gives them hives or some of the usual allergic symptoms. But staying away from a known allergen has no affect on IBS symptoms. What can you do? You have foods you suspect so you may look on the internet and try diets suggested eg milk or wheat free, low histamine or low tyramine, or being additive free, low chemical, and many others. Or your doctor may suggest a diet direction. If you want to work out a diet for yourself you can look at my suggestion below. If you want to ask “Is food intolerance is an inborn error of metabolism?”, or when “Thinking about cures for food chemical sensitivity symptoms” you can look at in the Articles section on my site https://foodintolerancepro.com/articles/
Imagine if you worked with allergic condition before allergy tests were available. You might leave out all the foods most often reported to obviously aggravate symptoms – the usual suspects: dairy, wheat, fish, shellfish, soy, nuts and others – and you may have symptoms improve. Then you would very carefully gradually challenge with each of the exclusions and see which one, at which amount, produced symptoms. Gradually you would produce the diet for yourself or your child.
We are at that same point of not having useful tests for IBS or for any of the other conditions that respond to the Low Chemical Diet. Many people, including me, have been looking for over 40 years now. We do know that allergy tests do not help with IBS. What foods are most often reported as aggravating symptoms here? I have the list on p 25 of my book Your Diet for Your IBS.
Some work has been done on the Low FODMAPs Diet so some gastroenterologists recommend it, but it may reduce some symptoms or even worsen some so it is often not the full solution. Some in the US use the LEAP tests but I note that dietitians still individualise it, and challenges are needed so dietetic supervision is still wise. Using my book Your Diet for Your IBS you can find the best elimination diet to begin with and be guided through your own preferred challenge foods.
Look into microbiome. And lifestyle. Usually some chemical or infective insult is the final straw that disrupts immune system at many levels and leads to IBS symptoms. Long term effects of this and subsequent stress causes some bacteria to overgrow, becoming dominant and reducing the balance, causing waste products, gas + pain, more immune stress. Food sensitivity is included in all this, it’s one of the symptoms/effects, one part of a bigger picture but exclusion is definitely one way to reduce symptoms temporarily. The more diverse the gut bacteria, the less illness generally and the less reactive our immune system is. Chronic hyper immune state causes many other breakdowns in other parts of the body. Our stressful modern lifestyle with all the chemicals abounding in our current environment does not help at all. Microbiome plays a big part in IBS and Small Intestine Bacterial Overgrowth. (SIBO). Takes a lot of work and reviewing of all sorts of research and a long term plan to combat this. And big lifestyle change.
Dear Mel, There are a variety of probiotics on the market, however there is inadequate evidence on which are the most effective probiotic strains, doses or regimens for each person. Ashleigh and I suspect that the gut flora that is right for you is the one you have when your symptoms are minimised. This usually involves diet investigation, but there is much research work being done in this area, so it is worth trying some probiotics. Test any recommended for you for at least 2 weeks, before you start any Low Chemical Diet, to see if you benefit. Yes, diet investigation is a good way to reduce symptoms, for some more than temporarily. Using Your Diet for Your IBS from this site you can incorporate the effect of stress or infections and using all the diet detective issues you have mentioned, and more, to keep expanding from your own elimination diet see https://foodintolerancepro.com/product/your-diet-for-your-ibs-ebook/ Since we now know that the best diet for each IBS person is not the same for everybody, as we show in Your Diet for Your IBS, we suspect that the probiotics that are right for each person is similar, so it will be interesting to hear what is developed in science over the next twenty years.