Thanks ladies. I wasn't aware that it peaked at around the 7-8 week mark. It makes a little more sense now, he had his immunisations at 7 weeks and had been suffering from wind issues before that.

EJ, how long was your DD on Zantac for and how long did it take for you to see results? DS2 started it 5 days ago now, I think I've seen a little bit of improvement, but can't be sure. He's still struggling to sleep during the day because of it, the only place he will have a decent sleep is in the swing. The GP said it takes about a week to start providing real improvement, so fingers crossed tomorrow might be a better day...