My first mistake was with Miralax - took child dose and still ended having the worst kind of cramps and diarrhea ! After that I never used it. Tried MOM but again took half the dose and got my BM runny (lasted whole night and whole morning). Than my CRS told me that I should "titer" myself and not go by the instructions on the label _ well, one should hope doctor would advise that before the accident , but never mind >: / !!!! She said try 1 TSP first to see how it works - and of course - it was the right amount for me which is 1/4 of recommended dose.
Try to drink some metamucil because it has two-way action - it can help you go if you have constipation, but at the same time it absorbs all extra water from the guts so it helps with diarrhea too. Don't be afraid to eat because your d. is not caused food or bacteria or virus but by osmotic agent. Eat some rice or bread but not too much - you don't want to get constipated ! I panicked when I got antibiotics and got d, and started eating rice gritz - well major mistake !!!!! Did far more damage than with plain d.. As Kim said - if it is not "explosive" it will not hurt your f., I mean shouldn't and burning always go with d., even if you don't have fissure - extra acidity as others said .
Best of luck, and let us know how it goes !