Thankfully, Abi is on the mend. She has since tweeted fans to tell them she is now out of hospital and that there is "no serious damage".
Abi - pictured far right - had to be rushed to hospital on Sunday evening
"Thanks for all your lovely message, I'm sure will be right as rain in no time," she wrote.
In another tweet, she explained what happened. "I fell down some stairs, landed on the edge of one on my back – thankful it's not worse + confident I'll continue performing x."
Xtra Factor host Caroline Flack revealed the news of the accident while explaining Abi's absence from the spin-off show.
The 19-year-old has since tweeted to let fans know there is "no serious damage"
"She has actually hurt her back so she has gone to have her back checked," the presenter said. "She is absolutely fine. I think she’s going to be ok."
It was certainly a dramatic weekend on The X Factor, which saw Shelley Smith eliminated from the competition.
Abi was actually the second contestant to be taken to hospital, following a medical emergency involving SeSe Foster on Saturday evening.
Pregnant SeSe Foster - pictured centre - was unable to perform on Saturday's show
The pregnant singer, one third of girl group Miss Dynamix, was taken to hospital shortly before the start of Saturday’s show and, as such, was unable to perform.
Speaking about the incident, groups mentor Gary Barlow said, "The other two girls are devastated. We are all devastated. She's nearly six months pregnant so we couldn't take any risks. We've heard she's fine but she won’t be on this stage tonight."
SeSe later took to Twitter to clear up rumours about what happened. "Incase some of you misunderstood, tonight was NOTHING to do with me being pregnant," she wrote. "I had an anxiety attack, it's hapned a lot in my life.
"I apologise to everyone for tonight, I begged and begged and begged however the paramedics say NO! I'm so sorry, I'm crying my eyes out xxxxx."
She later told the Sun, "It was very scary for a moment and I was praying that everything would turn out okay. But thankfully, the baby is absolutely fine.
"I love being in The X Factor but my health and my baby's health comes first."