When we have tummy upsets here, we fast for 24 hours (trust me, it WON'T starve the dog), provide water at all times, and wait and see. After 24 hours, we feed bland (boiled hamburger and rice, nothing more), and gradually, over a couple more days, reintroduce the normal diet.

If things don't improve in 24 hours, off to the vet we go. Diarrhea is nothing to mess around with, because a dog can dehydrate quickly if he is moving his bowels often. If it's not often, it's not much to worry about, unless it's prolonged (longer than 24 hours).

Some people, including vets, might recommend Immodium for dairrhea. I don't like it, because it works by slowing the gut. That means that whatever it is causing the problem is stuck there longer, potentially making it a longer-term issue.