please help

As a sufferer of stress related IBS myself I've recognised the same symptoms in a good friend of mine. Only problem is she won't believe me when I tell her what it is. She believes it's food related (which can be part of the problem) or today that it's appendicitis or a stomach bug. She has a lot of stress in her life at the moment, her wedding approaching... which her Nan and Mother are trying to control every aspect of. Also dissertations due in at Uni, changing job and her partner being away in the army. Theyre also moving into their new home after the wedding. I have had similar symptoms to hers but come out the other end of it and am desperate to help her through it. She seems to believe what she reads on the internet so can anyone give me some good links to websites I can show her to help? Thanks in advance