Odd odor from my abdomen

So while I'm dropping a deuce in the can, Sometimes it's a pretty painful one so I find myself holding my stomach and i've noticed when i remove my hands from my stomach they smell like sh*t. I hadn't wiped or anything yet. I've put my forearm or even my shirt against my stomach when I'm on the can and they both absorb that smell. It seems to be gone by the time I leave the bathroom. I worry often that I'll have some odor left over. I wash my ass and all thoroughly. Is it possible that this odor is leaking from the pores of my skin around my stomach?