A burp which is edured by either a person who has had some sort of violent bowel disfunction where turd has leaked into the stomach causing irreversible poo gas which is vented through the mouth or someone with type 2 diabetes and bowel cancer causing a small implosion of turd and insulin resulting in hectic gas production venting in the form of either a watery sounding far tor a poo-burp
Scene from broke back mountain:
Cowboy 1: What in the lords name is that God-aweful smell Enis??
Enis : Oh sorry I must of accidentally fisted my anus too hard causing an irreversable poo-burp, can you please ring an ambulance...