The vagus nerve is the major nerve going to the abdominal organs, sending information to them and receiving information back. A major theory about the underlying cause of IBS is that there’s an increased sensitivity to intestinal distension — bloating — although there are many other possibilities. So, in a sense, IBS is at least partially brought on by the vagus nerve — even though the actual abnormality may be either in the gut or perhaps in the signal processing area of the brain.

People with IBS generally find that certain foods trigger symptoms; however, I was able to find reports of people in whom meal temperature was a major catalyst. Both too-cold meals and too-hot meals can bring on IBS. If a too-hot meal was a problem, it makes sense something cold may help, although some people can be triggered by both.

IBS is a diagnosis that should be made only after evaluation of other causes. Some of these are serious, such as inflammatory bowel disease. Evaluation usually includes a colonoscopy and/or an upper endoscopy. A new test, the fecal calprotectin level, is helpful at excluding IBD, especially in people with low inflammatory markers, such as C-reactive protein, in the blood. Celiac disease should also be considered. Vomiting, however, is not a common finding in IBS (even though it does happen in some people) and that should bring up the possibility of gallbladder disease.

Treatment for IBS needs to be individualized and starts with avoiding triggers. In your daughter’s case, that clearly includes hot foods, but gas-producing foods — beans, broccoli, onions, dried fruits and many others — are commonly on that list as well. Lactose, a sugar found in milk, is another. For people in whom simple dietary advice is not helpful, I recommend a visit with a dietitian nutritionist to consider a low FODMAP diet (fermentable oligo-, di-, and monosaccharides and polyols; these are difficult-to-absorb carbohydrates found in many foods).