This article is from the the official alt.spleen FAQ, by Andrew Stellman with numerous contributions by others.
Andrew says: NOTE: PLEASE DO NOT SEND ANY MAIL TO ME REQUESTING MEDICAL ADVICE! I AM NOT A DOCTOR, AND WILL NOT GIVE YOU ANY USEFUL INFORMATION.
Yes, he did, and many attribute the downfall of pop art and the rise of conceptual art to this very incident. Valerie Solanis popped off a few rounds into Andy, inspiring the movie, "I Shot Andy Warhol," which features one of Lisa's old coworkers, Craig, playing a gay guy.
Gerard Malanga has this to say:
"It was bad. He almost did die. His pulse was so low that he was pretty much pronounced clinically dead. There was at least two, maybe three bullets. He lost his spleen. He lost part of a lung or a liver. For a year he had to wear a corset to keep his intesties in place."
(from McNeil & McCain, 1996)