Again, a bit late, but it would be best to actually see an op note/post it with your question. I'm assuming that the procedure is a revision of the previous Roux-en-Y? But what is needed is the actual details of the revision in order to pick a code. Either way you would have to use an unlisted code because there are very few laparoscopic stomach codes, but knowing exactly what work they were doing would direct you to what unlisted lap code you would use:
unlisted lap procedure stomach - 43659
unlisted lap procedure intestine - 44238
unlisted lap procedure abdomen, peritoneum, omentum - 49329.
Also, EGD is a separate procedure and unless it's being done for a totally different/separate reason, other than to look at, or assist, with the bypass revision, then it is not a separately billable procedure.
A great example as to why the op note is really needed to help, is, like above - you state 'specifically the gastrojejunal anastomosis'. I just actually had to do one of these and the Surgeon stated it was a 'revision of the gastrojejunal anastomosis', but when I got into the op report they were actually reconstructing the small intestine to lengthen the biliopancreatic limb to limit absorption, (because the regular Roux-en-Y failed). So it was a gastric bypass revision, because the whole procedure is considered the 'gastric bypass' but they were nowhere near, didn't touch, the gastrojejunal anastomosis at all. And that is actually one of the very rare laparoscopic stomach codes that we do have = 43645.