I'd say he's perhaps been feeling a bit under the weather all week, from what you say. Messing in his crate - there will be a reason. Eating grass usually makes them throw up rather than have effects at the other end. It is normal - Jess seems to have a particular liking for one sort of grass and will chew it for ages, we think she just likes the taste - but it can also mean that they aren't feeling altogether well. Hard to tell which it is!
I'd stick to a light diet for a few days until it is clear that everything is fine again. White rice and either chicken or white fish. Be careful with yogurt, dogs cannot digest lactose and although there is less in yogurt than there is in milk, most commercial yogurts still have a fair amount.
