Have you looked into the SCD (Specific Carbohydrate Diet)? It's a low carb diet that starves yeast/bad bacteria. Also, an antifungal diet may help. I had UC for 8 years before experimenting with an antifungal diet (eat lots of protein and veggies among other select foods). I am now symptom- and drug-free for almost 6 years now. I would also recommend a reputable probiotic. Has he tried an elimination diet? (such as no artificial sweeteners, soda, wheat, dairy, etc.)Was he ever on antibiotics?..or you while you were pregnant? Could be a fungal component to his symptoms, if so.