Kristin Evans -- the woman who was brutally attacked by Zac Stacy -- is back in the hospital dealing with injuries she suffered in the violent incident, TMZ Sports has learned.
Sources tell us Evans, who initially received medical care in the hours following the attack, returned to the hospital Friday morning after she was still experiencing the lingering effects of Stacy's rage.
We're told Evans has been throwing up the past few days ... and is also suffering from back, rib and torso pain.