I just had one quick suggestion. If that peppermint tea helped you, but only temporarily you might want to try taking Peppermint capsules. I think the capsules are stronger, and they are convenient to take as often as you need.. Assuming you don't have any problems with acid reflux (indigestion, heart-burn, etc).
I know that Heather has made some peppermint oil capsules that she swears by, and they also have fennel and.. um.. something else in them. I'd try ordering them and giving them a try and see if that prolongs your relief. Otherwise, you can usually find peppermint oil capsules in health food stores.
Good luck! --Steph
-------------------- ~~I'm not crazy, I'm just a little unwell-I know right now you can't tell~~Matchbox 20
IBS-D,pain.