I have diverticulitis too, but fortunately my two attacks have been mild.
He’s a little young to be having it - even 40 years old like me is still pretty young. For those who don't know, it's basically an infection of a diverticulum - a small little inlet in your intestine that develops in virtually everyone as you age. Pain can vary - I definitely knew "something" was there, but it was tolerable...and the second time I hopped to the ER within 3 hours because I knew exactly what it was. Usually, if it's uncomplicated, you wind up on antibiotics for 7-10 days, and clear liquids for a day, bland diet for the rest of the week. You can still be pretty wiped out for awhile. The worst part is that they usually want a colonoscopy afterwards - you can't have it during an active episode, because of the risk of perforation. They scheduled mine a month after, and it had definitely died down by then. I have a feeling Backes probably won't be back until he's had his....maybe they'll be more aggressive and give him a CT in 2-3 weeks to see if it's died down.
TL;DR: Kids, eat your fiber! (And drink water, too...although personally in my case, that's never been an issue.)