MÖTLEY CRÜE frontman Vince Neil's girlfriend, Las Vegas celebrity makeup artist and beauty educator Rain Andreani, told Robin Leach of the Las Vegas Sun this morning that it was "unknown for the moment what the illness is" that forced the singer and his bandmates to play an abbreviated set Sunday night (March 10) in Sydney, Australia. "[Vince] will get the results of the scan Monday morning Australian time" and it was possible that he would undergo an operation, she said.Neil was reportedly rushed to a hospital in Sydney by an ambulance from the stadium and immediately underwent a CT scan. Vince complained while onstage of internal pain and said it was so severe that he couldn't continue. Guitarist Mick Mars took to Twitter a little later to say that the singer was suffering from "kidney stones." MÖTLEY CRÜE bassist Nikki Sixx has since gone on to explain the entire situation via Facebook. "As many have heard, we had to cut our set short by four songs last night due to Vince being in severe pain on stage," he wrote. "He was doubled over on his dressing room floor five minutes 'till show time and was told by the promoter to not even play, but Vince said he couldn't do that to the fans. "I've seen Vinnie go onstage with broken bones, his voice completely blown out and torn ligaments, but he never ever cancels… Just like an athlete, you sometimes have to play through the pain, but last night it became to excruciating. "I was texting with Vince most of the night last night as he was just waiting for the doctor to come back with the test results. This morning we found out he had to be admitted into surgery to remove kidney stones. He just got out five minutes ago and the doctors said everything went well in the operating room. "I am going to the hospital to see him before I head to Brisbane." Neil also checked in from the hospital with the following message: "Just out of surgery. Spent night in hospital probably have to again tonight. "Thank you all for the kind words and prayers. "Doc says I should have a full recovery and be back onstage for the Brisbane show tomorrow. "Thanks to my bandmates and crew for your support!" CRÜE played seven songs during its Sydney set before Neil had to leave: "Saints Of Los Angeles", "Wild Side", "Shout At The Devil", "Same Ol' Situation", "Sex", "Home Sweet Home" and "Don't Go Away Mad (Just Go Away)". Drummer Tommy Lee and Mars also took part in individual solo spots at the very end. Sixx then took to the microphone and told the crowd that Neil had been in pain throughout the show and had been taken to the hospital.