According to reports, the singer fainted shortly after the show went of air, just after viewers saw 4th Impact talking to presenters Olly Murs and Caroline Flack about their exit from the show.
A source told The Mirror: "Everyone was saying their goodbyes to the girls and then suddenly Celina hit the floor. Her sisters were shocked and Cheryl started calling for people to help. Two men ran on stage and carried Celina backstage."
Meanwhile, frequent X Factor guest star Sinitta tweeted: "#Selena from @4thImpactMusic just collasped on stage and carried off by paramedics @TheXFactor (sic)."
The girls' mentor Cheryl Fernandez-Versini appeared a bit shaken at the very start of Xtra Factor, confirming to Rochelle Humes that Celina was being treated by paramedics backstage.
Rochelle later said: "Celina has unfortunately taken ill and is with her sisters so we'll be chatting to the lovely Cheryl instead."
Cheryl told her: "I could see her, I was talking to her and she wasn't engaging so I brought her closer to me to ask if she's okay and she just went, she passed out. She is fine though, she is with her family and her mum is here. She's fine, I promise you, she's been sorted out right now."
4th Impact later updated fans on Celina's condition, tweeting: "Thanks to all who voted for us why we reach this far. Celina is ok now thanks for your prayers and love. Love u guys. Lets keep believing."
Poor Celina previously fainted before the band's Movie Week performance on X Factor earlier this month, but managed to make it to stage for the show. However, at the end of their rendition of Beyonce's 'Work It', she appeared dizzy again and was given a chair to sit on while the judges gave their critique.
4th Impact were eliminated last night after landing in the bottom two alongside Lauren Murray. The judges were split on who to go home, sending the results to deadlock, which revealed 4th Impact had received the fewest number of public votes.