Sorry to crash your discussion, but I just wanted to say that, actually, I think it can be a good idea to leave a bottle or sippy of water in the crib for your LO to find - many adults wake up in the night for a quick sip of water. I have seen lots of other discussions on the boards where a lot of mums also say that it is fine to leave some water for your LO ( and I recall a case study that Tracy did in one of her books where they did this exact thing).
However, having said that, you have to make up your own mind entirely on this one (especially as your LO is quite young - there is a very small risk that he could choke on the water and you wouldn't hear - hope I haven't frightened you with this thought) . If your LO does not need a drink of water every night (which would seem to be the case given that there are lots of nights with no NW), then you might not want to run the risk of creating a 'reason' for your LO to wake.
It all depends on how your LO would manage the situation - if you are confident that he can grab the bottle or sippy, take a few sips and go back to sleep on his own without waking you, then it is definitely worth a try. If he needs you to come and hold the bottle or sippy for him, though, then it is not a good idea, as this will become a prop that you will have to partake in. You know your LO best, so it is up to you
Regarding him being thirsty whilst you are doing WI/WO, as Elmarie said, WI/WO could take some time for your LO to get the hang of. If it was me, I would have a bottle of water or sippy handy whilst you are doing WI/WO and either set a time in your head (e.g. after half an hour of WI/WO) or listen for thirsty cries, before offering a quick drink of water and then immediately leaving the room. This is perhaps not 'recommended' technique, it's just what I would consider doing if it was me.
Even now (my LO is 27 months old), I find it hard to know exactly what the reason might be if my LO wakes (which is still quite often, actually!). Sometimes, it seems, there is just no reason at all
Teething definitely played a big, big part in NWs when my daughter was your son's age, though, but this did not always respond to pain medication. Gas is also a bit of a tricky one - by this age, your son 'ought' to be able to pass gas without too much difficulty, but we are all different - I get a hard tummy from swallowing air when I am nervous, for example.
I don't have any other ideas or advice to you, but I want to send you (((hugs))) and best wishes - you are doing a wonderful thing for your son and yourself.
