I have both IBS-C and IBS-D. IBS-C seems predominant, but when it flips to IBS-D, I am glad there is immodium. I have found times when it stops IBS-D in its tracks with 1-2 doses. Other times, the medicine just helps me to live a normal life. For example, I had a case of IBS-D where at work I was under great tension. Because of the fragile state of the intestines, I found myself needing to "go" every 5 minutes. How can a person hold a job that way? With Immodium I can have a social life. So, at times I have had the experience that Immodium seems to cut short an IBS-D attack. Other times it makes such a period more endurable.