I searched, and I hope like hell this isn't a dupe.

A rugged cowboy from Brokeback Mountain, Wyoming, goes into the doctor's
office and has some tests run. The doctor comes back and says, "I am not
going to beat around the bush, You have AIDS." The cowboy tugs at his
Stetson and sets his jaw and says, "Doc, what can I do?" The doctor says,
"I want you to go home and eat 5 pounds of spicy sausage, a head of
cabbage, 20 un-peeled carrots drenched in hot sauce, 10 Jalapeno peppers,
40 walnuts and 40 peanuts, 1/2 box of Grapenuts cereal, and top it off with
a gallon of prune juice." The cowboy squares his rugged shoulders and asks,

"Will that cure me,  Doc?" "No, but it should leave you with a better
understanding of what your asshole is for."