Difference between spit-up and throw-up?

Peter rarely spits up anymore, although he used to be a huge spitter-upper. Now if he's tired, he can be a little bit spewy.

But today he's chucked several times. They haven't been small chucks (more like a couple of tablespoons rather than a couple of teaspoons), and they have been gross because they are mainly solids. They haven't seemed to cause him any distress at all, they just pop out like normal spit-ups. He's been a little off his food, but nothing dramatic.

He's asleep now, but keeps waking up with little cries.

How can you tell if he's just tired and extra spitty-uppy, or sick and vomiting?

Hmmm if it was me I would be tending to think that he might be a little sick if it's unusual. Try to keep him off dairy for a day and see how he goes.

It sounds more like spew to me.. If he is off his food, he may have a virus.. Keep his fluids up.