You are in an almost identical situation as me and husband. 11 months and still no solution. First, I feel the Immodium is very bad for your system - it's harsh as hell on your gut. Get thee to a doctor and get Lomotil (RX only) and perhapys somethig like tincture of opium.
We have been going through this for a year - and there are no answers that we have found - it is a frustrataind fight every day. If you would like to talk off the intenet, let me know. I can set up a quick emai address and then dump iimmediately and we can talk without others involved.
I have had "IBS" - as they call it because they couldn't find anything wrong for 15 years...I was the same as you....I have learned to live with it...by trial and error I have found many foods I cannot eat....the main things I had to cut out were the following: eggs, lettuce, anything with caffiene...including coffee, tea, chocolate, and any pop....
any of those foods or anything spicy....and most milk products would sent me instantly to the washroom....some days I could drink water and run anyway....
I take 4 - 15 immodium everyday....but it is the only thing that keeps things calm....also have begun to take ibrophen.....every morning...it keeps the intestines inflammation down which helps a lot....
the last thing that I find helps...and it takes a couple of weeks to kick in is drink lots and lots of water...sounds crazy...but it really helps....I had 2 years ..I couldn't hardly leave the house...it is much better now as long as I do the things noted a bove....some bad days but mostly pretty good...as long as I follow the "rules"