@so lucky - I went on vaca and left a dog with a sensitive system in the care of a person who is .... somewhat logic deprived.
He is super sensitive to most commercial dog foods, an additive sends him into seizures. Anyway, the ONE food that I've found that doesn't do that to him - gives him mild diarrhea. For a while I figured it was the lessor of two evils. As long as it was just soft, and outside, no big problem. But, I was trying to help him and had started him on some digestive enzymes - which are a yummy little soft treat.
Well, when I left, he stopped eating his food.. but he was still happy to scarf down the enzymes. So for a week he was eating nothing but 'treats' that were revving his system in to turbo-charged digestion. By the time I came home he was painful, skinny, still not eating, etc.
I started him on a bland diet, and some meds but it's just a waiting game for the lining of his stomach and intestines to heal. For a LONG time I was waking up to the sound of splattering on the bedroom carpet...

... every 2 hrs ... all night long...

Now we've gotten to where he wakes my up about 2am and gets let out. If the weather is bad, I wait for him. But if it's not bad, he's out and I'm back in bed till the alarm goes off at 4.