Very unrealistic (some SPOILERS)

I'm not talking about the basic premise, that the guy wants to get punched to pay off his debt. I'm talking about the effects of the beatings.

From the punches to the face there's not one broken tooth, seemingly not a broken nose, just minor swelling, and he never passes out. From the punches to the stomach, he never throws up, and never coughs up blood. In real life his insides would be completely ruined and he would have blood in his urin and crap (we actually see his urin in the film). He would end up in the hospital after just a few days! He starts to lose his hearing at one point in the film but thankfully he magically regains it after a few seconds. :p

All this made me not believe in the story at all.