Hi,My answer here is from my experience alone -- different people tend to have different reactions to different treatment, so take that into consideration.I usually take Immodium in the morning, and it keeps my bowels inactive until the evening. I noticed that it has the best effect this way -- if I take it later into the day, after I've already eaten, it often doesn't work as well.Calcium, as per Linda's explanations, is a cause for constipation, and as such, provides an "opposition" to the gut's tendency to overwork. These you should take 3 times a day with your meals.Immodium isn't a long-term treatment. Calcium is.Hope this helps.G.