The act of inserting a fluffysticky soft candy into the anus in any amount to be dissolved in the colon before anal sex/masturbation to purge the lower bowels of all fecal matter. After purged, it can be done again to fill the colon with a clear sticky fluid for the enjoyment of others. Marshmallows are a powerful laxative. Marshmallow stuffing should not be done by diabetics or anyone else concerned with blood sugar. Should be done in moderation to avoid pooping yourself at work.
I stuffed 6 campfire marshmallows (marshmallowstuffing) about 30 minutes ago and I can't hold them anymore!
A subcategory of feederism where one obtains sexual gratification either from feeding a partner or from being fed, usually past their limits. Someone into belly stuffing will most likely find round, stuffed bellies or the state of being full or overly full attractive.
Other related kinks may include moaning, forcefeeding, aftercare, exhibitionism, submissive/dominant, etc.
"I'm into bellystuffing so I guess you could say I like my men well fed!"