So we ended up in the hospital, and then booked in for surgery (appendix) and then un-booked, and told it was a viral or glandular thing, which should nick off in the upcoming days.

He's sleeping now.

He's still got discomfort, but it's good to know that it's cramps from that, and not something more serious.

So lots of fluid, lots of rest, warm baths, hot water bottles, etc.