I just got through law school, so I know am very familiar with the stress that accompanies grad school. You certainly have more on your plate than I did, what with having two children as well! I am glad you're feeling better
I do still take Immodium daily and only take one pill a day. Being on Effexor sometimes makes me feel a little "stopped up" so if I get that feeling, I skip a day on the Immodium. Once you get on the med for a while you'll see what I mean. I just listen to my body in the morning and can tell if I feel I need one or not. There are some days when I get a little over zealous with the IF (I love my veggies) and may need two Immodium. I never notice any problems with that.