Congratulations on reversal! Like Sue said, it's different for everyone. I actually had reversal twice- had to go back to ileo. 2 weeks after first time because of complications, which shouldn't happen to you- so I have two experiences to compare. I think the first time it took 3-4 days to start pooping. I honestly had a terrible time the first reversal. It was very hard to control my bm's and I was miserable. Thankfully, the second time was much, much, much better for me. It took 6 days for me to begin passing gas and pooping. I was incredibly bloated until I started passing gas- my abdomen was so hard from all the air trapped inside I thought I would burst, lol. Once I started going to the bathroom, I had near perfect control. I remember the first time I went, I just felt like I needed to let something more than a fart out and so went to the bathroom. No urgency, no big deal. It did take at least a few weeks to begin to be able to pass gas without stool coming out as well, though.
It's good that you are passing gas, it means that your intestines are pushing things along! Are you vomiting? If you are not, there should be no reason for the NG tube. Just keep walking, and before you know it, you'll be pooping the old-fashioned way again. :)