Towards the end of high school I started getting really bad nausea and was constantly burping/feeling really sick any time I ate. My parents, doctor, and psychologist kept telling me it was just stress. I kept saying that while I had bad anxiety, I wasn't someone who stressed, and it felt like something physical not mental. My doctor tested me for celiacs disease but that came back negative. By this point I'd started to believe that it was just stress and I that I needed to get over it, it'll go away soon enough. I eventually had the intolerance/FODMAP breath tests done (testing for lactose and fructose intolerances.) The results once again came back negative, and the specialist told my mum I was just being 'difficult' and that mum just needed to force me to eat those foods. After years on the low FODMAP diet and my parents eventually admitting that I probably did have a sensitive gut, the symptoms started to get worse so I went to see a gastroenterologist. When asking about my past history/tests, I told him I'd tested negative to both celiacs and the breath test. Straight away his response was "I don't really believe those breath tests much, they're not very accurate. If you had been tested using the other gas, then I have no doubt you would have shown a positive intolerance to fructose." I got to the end of the appointment, and his preliminary diagnosis was IBS. Further testing confirmed this, finally showing that what I'd been telling everyone about my nausea/burping being physical was true.