Id be willing to say he is sausage butt....and by his next shed, you will get a bunch of it...

My mojave ONLY defecates/pees during his shed... he still has urates but never any fecal matter UNTIL he sheds skin, if there movement in lower half still as skiploder said Id be willing to bet hell let it out once he sheds, my big female can hold it for aslong as 3-4months sometimes,