She has become the second of this year's campmates to leave the show for medical reasons.
The journalist and MasterChef star said she was "so sorry to let you down".
Fremantle said it was "sincerely sorry" for the "distress" caused to David Walliams after recordings of his "private conversations" were published in the media.
The former UKIP leader has been at the centre of controversy ever since he signed up for the new series of I'm A Celebrity.
The Zoey 101 star sparked a strong reaction online after she appeared to dodge any mention of Britney.
Here's exactly how viewers voted during the Big Brother final.