Warning: possible TMI alert wrt poo 
My DS is 9 months. Yesterday, his poos basically started looking like whatever I'd fed him had gone straight through, only more watery. Then today he did an explosive, runny, green poo (after I'd taken his nappy off, of course 
). He's also very tired, but struggling to sleep - he fights and screams, then once he's gone the slightest noise wakes him up and I often have to cuddle him back to sleep. He sleeps fine if he's on me, but obviously I have housework to do and can't sit on my arse all day bored being a bed. He also seems to have gone off solids, though this may be due to the fact that I tried to feed him outside, making the most of the sunshine!
He's perfectly happy otherwise, still surfing along the sofa and happily playing, still drinking anything I give him.
I rang the HV after the pooplosion as he'd never done a green one before and it seemed to upset him, and she said it could be a virus, or it could be that he's teething. (He is drooling a LOT at the moment, we think his matching top two teeth are coming in), but she was really vague and couldn't give me any real idea of what could be wrong.
Is it just teething, do you think? I'd have thought if he had a virus he'd be more "ill", really grumpy, or have other symptoms.
I'm probably overreacting because DP isn't going to be home until late so if anything IS wrong I'll have to deal with it on my own and I'm very good at panicking!