Debby,
I'm speaking only of my experience... but my symptoms of IBS-D dramatically improved when I started Alli. I attribute it to the correct way of eating. While I had IBS-D, I didn't stay clear a of few trigger foods. Every day, I'd be in the bathroom, on the floor for a couple hours... wishing it would get better.
I ended up cutting out any fried foods, no fast food, no cream, no mayo, no butter, no soda... This was gradual, and one day I went to eat out with my parents, and they were like "Where are you 10 immodiums you are going to take". Then I realized, I hadn't taken them for a long time.
I also attribute the improvement of symptoms to daily exercise leading to stress relief... I know at least with me, stress would trigger IBS-D symptoms in me.
Finally, let the pharmacist answer the question about mixing Alli w/ Immodium. But I never did. And when I did experience the Oily Discharge it wasn't bad at all.. It was like a walk in the park compared to my IBS-D symptoms! You don't really want to take immodium to bind ya, when you are trying to let that oily discharge go...
I also know this has been discussed on the board a number of times, so maybe a search will also help you out.
Good Luck!
Mich