Well ladies, turns out the blood in the diaper, painful urination, little lesions and today's new symptom, blisters, is a yeast infection. Who knew? Saw the urologist this afternoon and he said it's really quite common. So now we're doing a topical steroid/anti-fungal treatment for two weeks.
Poor little man. I hope this helps him feel better, and he starts eating again soon.
Thanks for all your T&P