Slindsay, I haven't tried the VSL yet myself but was planning to start with 1/2 packet (or 1 pill) per day to begin, and work my way up slowly - everything I've read is that you don't start with the full dose at once, though certainly your doctor is more knowledgable than I am
You might want to research a bit but I would start with a very small dose per 7 days and adjust slowly.