The influencer and business owner said that she spent half a day sitting in A&E with the mystery illness.
She shared the news with her 372,000 Instagram followers as she posted a video of an IV drip attached to her arm.
The 32-year-old wrote: “Not the best 12 hours. Spent the night sitting in A&E in agony with tummy pain…
“Thankfully home now and hoping to get to the bottom of it with tests but that was extremely tough.
“The hospitals are so overwhelmed,” she added.
On Sunday morning, the mum-of two thanked her followers for their “kind” messages wishing her a swift recovery.
She also hailed her husband Paul Quinn for helping her out with their kids, son Harry and daughter Remi, as she got some rest after leaving the hospital.
“Thank you for the messages over the last 24 hours, you’re all so kind. Feeling a lot better today and managed to get lots of sleep in yesterday...” she wrote.
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“Will get to the bottom of it this week but thank you for the kind messages! Thankful for my husband and family who looked after me and picked up the slack with the kids so I could rest.”
Rosie also fell ill earlier this year when she tested positive for Covid-19 “after two years of dodging the bullet.”
Back in April, she told her Instagram followers that she was suffering the “worst 12 hours of sickness” she’s had in years.
She then shared a photo of a positive antigen test with two distinct red lines indicating that she’d caught the virus.
“I think after two years of dodging the bullet, we’ve got a mam down,” Rosie said.
“Waiting on an antigen to be brought home to me but wow, worst 12 hours of sickness I’ve had in the longest time! Fever, chills, nausea, migraine...
“If it’s not Covid then it’s a pretty brutal flu,” she added before her test results came back.
The mum-of-two also said that her eyes were “killing” her and felt “so sensitive,” so she was going to bed to get some rest.