Welcome to HealingWell!
Have you actually been tested for Celiac's? If you know you cannot tolerate gluten then I would do anything possible to stay away from it. Probiotics can also help you.... Do you take any? Probiotics are especially helpful and neccessary for those on, or who have just taken, antibiotics. They will help replenish your good bacteria that gets killed off by the antibiotics.
Have you heard of Digestive Advantage for IBS? Many of us have tried it, or are on it, and had good results.