Freddie Starr was taken to hospital just hours after chomping on some stomach-churning food during I'm A Celebrity ... Get Me Out Of Here!
The 68-year-old funnyman ate mice tails, among other things.
He had to be seen by medics and was taken from the camp for tests, but is said to be in "good spirits".
Freddie – who has had heart surgery – was taken ill just two hours after taking part in the show's "greasy spoon" bushtucker trial.
The comic had already been late arriving in the camp after a paperwork problem which arose as a result of his heart attack.
It's thought his illness was some sort of allergic reaction – possibly to a bite or brushing against a tropical plant – rather than his gruesome meal.
A spokesman for the ITV1 show said: "Freddie Starr was taken unwell in the jungle.
"He was immediately attended to by on-site medics and taken to hospital where he was assessed by doctors.
"He will remain in hospital overnight as a precaution and further tests continue, he is in great spirits and keeping nursing staff entertained."
Freddie was chosen by viewers to take part in the trial with reality star Mark Wright.
He was unfazed as he munched his way through five courses of unpleasant grub, beginning with a fermented egg.
The next course included bugs, cheese fruit, mealworms and mice tails.
He rounded off the meal with cooked camel toe, then turkey testicles, as his competitor looked on in wonder.
"You are a lunatic – you would never have stopped," Mark Wright told him.