Lovely snake mate, a real beauty.
As to pooping, basing it on my somewhat limited experience (having owned one IJ for approx 6 months), i would expect one "event" every 5 or 6 weeks. These critters really seem to like to hold onto the matter for as long as they can.
But it probably IMO depends very much on how much you feed it and other environmental issues...how much does yours pack down at feeding time?
One other point (and this is again just my personal opinion)...that cage set up is lovely, but it might be tricky to keep clean. And be prepared to change all the bedding entirely once it does "go". The amount of dump mine produces is nothing short of astonishing.