I am sorry that noone has reacted to your message. May be the question is difficult.
I don't know anything about IBS. So my suggestion is when "Ask Andreas Moritz " forum is open put your question there . He is a professional and he can help you. Since he is busy with his practice and writing books etc., he only takes 6 questions a day, so you have to keep checking. You can see the last batch of questions are not answered yet.
In the meantime I was reading the "Ask Shelley" forum, also a good forum for you, and there was a message about peppermint tea.
I thought of you. I will enclose the link and then click on the link at the bottom of the message about the peppermint tea.