I Have IBS With GERD Terminal Copd. But My Ibs

I have IBS with GERD terminal copd. But my ibs is the problem. I defecate when I pass gas, sometimes for no reason, most of the time it’s just regular feces. Dr. put me on prescription probiotics and that helped. Now I pass gas all the time and potty. My question is-can I take Imodium with the probiotics. I am 71 years old and with all my other problems, this is driving me nuts. Thanks.