for that,If you've been diagnosed with irritable bowel syndrome but haven't been tested for celiac disease, you should talk to your physician about ordering the celiac disease blood tests.
If you have been tested but came up negative for celiac, you might want to consider a trial of the gluten-free diet anyway. Currently, there are no accepted medical tests to diagnose gluten sensitivity, so the only way to determine if you have it is to remove gluten from your diet and see if your symptoms clear up.
Of course, it's possible to have both IBS and celiac disease, and many people with celiac disease find they still have intermittent digestive problems. In many cases (but not all), you can trace those digestive problems to gluten cross-contamination. But if you continue to have problems even after eliminating all possible hidden gluten from your diet, you may want to talk with your physician about the best ways to manage your IBS