My friend has crohn's disease and he is in SCD for 8 months. When he start the SCD, he saw improvement immediately. But after he introduce more and more food, he start to have diarrhea and smelling gas in the afternoon everyday. And he tried the introduction diet several times. During the introduction diet, he feels better, but when he try to introduce more food, the diarrhea and smelling gas coming back. What should he do? Any suggestions? Any supplement he can take ?