Former WWE Star X-Pac -- Anus-Ripping Nearly Killed Me

Former WWE star X-Pac tells TMZ ... he lost so much blood after tearing his anus apart during a wrestling match in Minneapolis last weekend ... he nearly died.

Pac -- real name Sean Waltman -- says he didn't notice the blood at first ... and even finished the match ... but during the after-party he felt something was really wrong. Pac says he went to the bathroom and discovered an enormous pool of blood in his singlet.

That's when Pac called himself an ambulance.

As we reported, Pac underwent butthole surgery that night ... and was released Monday morning. FYI, the procedure is called a sphincteroplasty (WARNING: Do not Google).

We've obtained video of the accident ... you see Pac flying anus-first into the steel turnbuckle ... the footage of the accident from RFvideo.com is pretty brutal.

As for going #2 ... Pac says it's business as usual, but he was given special instructions by his doctor on how to clean his wound after pooping.