35 year-old Katie, a.k.a Jordan, had an emergency operation, before being released the same day, according to a UK newspaper.
A source told the paper: 'Katie was obviously really worried, as was Kieran. It’s been a difficult few months, as she has been plagued by so many complications.
'This was yet another problem for her to face, but once she had the emergency op, which went well, she was able to leave hospital late that night to return home to her children.'
The mum of four hasn't commented on her health on her Twitter page, but has been tweeting this week about her new bridal range.
On Tuesday she posted a photo of a cupcake with a marzipan baby on it, writing: 'Baby Jett, he is as sweet as a cupcake xx.'
The glamour model gave birth to son Jett eight weeks before her due date in August, following a difficulty pregnancy. He was delivered by emergency caesarean in a French hospital.
She suffered an infection and the baby’s heart rate fell dangerously low. Once delivered, Jett, who weighed 5lbs, 2oz, was taken straight to an incubator where he spent several weeks.
To Katie’s distress, husband Kieran had not been allowed into the operating theatre.
After Jett’s birth she said: ‘Bringing life into the world is supposed to be magical. But what I went through was a nightmare.
‘The only thing that had got me through the nightmare was the thought of cradling my little boy.’
Kieran wrote on Twitter at the time: ‘Its been a tough 3 weeks but we are closer and more in love than ever before.’
The couple have been home in England since early September after Jett was deemed strong enough to leave hospital.