@morningstress poor you, I completely empathise - I'm a screaming emetophobe myself, I'd be anxious too. In fact my DH came over green and sweaty one day recently at the shops and asked me through gritted teeth if we could go home, like NOW as his innards were suddenly in turmoil.
He's never poorly like that so the old familiar panic gripped me...he's got a bug, he's going to start vomiting, etc etc. It was nothing, he'd scoffed a whole pack of those Aldi sugar free sweets which are, essentially, laxatives. 
If he's had just the three episodes and hasn't been again for over an hour, it's probably over - that much chocolate would have the same effect on me (IBS here too).
His bowel is making noise because there's only air travelling through. I'm no doctor but I would confidently say that if he was going to start vomiting, he would be feeling much sicker and wouldn't be acting/laughing normally! Just give the bathroom the once over with bleach - toilet, flush handle, tap handles, light switch/pull cord, door handle etc), and use your own clean towel for your own hands and face etc. I don't think it's a bug personally, it's probably a one off. Immodium is fine for that.
Anyway, my boss called when I was in the middle of typing that post so things might have moved on in the last 15 minutes, how are things now?