Your doc hasn't given you any antispasmodics?I'm not sure how to dilute the peppermint, but I do know tea can work wonders. Fresh mint tea and also fennel tea help me a great deal with pain and gas. I once posted on here about what various teas do, I dug it up, here it is:
Peppermint I hear is primarily for relieving gas. I can't say how to dilute it though... Hopefully someone will come along who knows. If not, try Googling it (I tried but didn't find anything good).