The first thing is to stay hydrated. You should be peeing at least a few times a day, and your urine should be light colored. If you can’t stay hydrated you’ll need intravenous fluids, whether the CT scan shows a blockage or not. Stay away from any solid food, and perhaps anything but fluids. Try to walk around as much as you can. The vomiting can be a sign of trouble, so you may need to return to the ER (unfortunately). I hope you feel better soon!

I think blockage passed, but nothing expelled since. How long for pouch to start working again?

Since ur pouch is just a reservoir, the question is, did you have some type of ileus where your small intestine just shut down for a while?

I would start very slowly with a soft white diet in small amounts and see if things move thru your body ok.

then increase intake as things improve.

Does it take a couple of attempts to clear a blockage?

I'm not sure what you mean by attempts. The typical blockage isn't at the pouch but at some other part of the small intestine. Some people do have trouble emptying their J-pouch even though it's full, but that often isn't exactly a blockage.

I had a small movement and thought it was over, but it is not. My cycle now is to drink water, electrolytes until it can't sit in me anymore,  vomit, then start again. 

Is it risky to use a laxative

I’ve never tried using a laxative for a partial blockage. Some GIs prescribe MiraLax for pouch emptying issues, but I’d be surprised if it helped the gut unkink itself. Lots of folks have reported here that the contrast medium they swallowed in the ER to prep for bowel imaging cleared up their blockages, perhaps because it’s quite heavy but won’t solidify.

Cleared up with an enema. Very weak, but out of trouble now! Thanks for the comments