...story that appeared in the Los Angeles Times. It says: "In retrospect, lighting the match was my big mistake. But I was only trying to retrieve the gerbil," Tomaszewski told bemused doctors in the Severe Burns Unit of Salt Lake City Hospital. Tomaszewski, and his partner "Kiki" Farnum, had been admitted for emergency treatment after a felching session had gone seriously wrong.
"I pushed a cardboard tube up his [bad word] and slipped Raggot, our gerbil, in," he explained. "As usual, Kiki shouted out 'Armageddon,' my cue that he'd had enough. I tried to retrieve Raggot but he [bad word] out again, so I peered into the tube and [bad word] a match, thinking the light might attract him." 
At a hushed press conference, a hospital spokesman described what happened next. "The match ignited a pocket of intestinal gas and a flame shot out the tube, igniting Mr. Tomaszewski's hair and severely burning his face. It also set fire to the gerbil's fur and whiskers which in turn ignited a larger pocket of gas further up the intestine, propelling the rodent out like a cannonball." 
Tomaszewski suffered second degree burns and a broken nose from the impact of the gerbil, while Farnum suffered first and second degree burns to his [bad word] and lower intestinal tract."
So that's what felching is all about.