A terminally ill Frenchman who planned to live stream his death on social media has accepted palliative care after refusing food and medication for over three days.

Alain Cocq, 57, had earlier announced he was refusing all food, drink and medicine after French President Emmanuel Macron turned down his request for euthanasia.

Cocq, who suffers from a rare genetic condition which causes the walls of his arteries to stick together, said he believed he had less than a week to live and would broadcast his death from Saturday morning on Facebook, which said it would block a livestream.

"I am sorry but I needed a some serenity to depart in peace," his spokeswoman quoted him as saying.

He was hospitalised on Monday, lawyer Sophie Medjeberg, who is acting as his spokeswoman, told AFP.

"He is suffering too much, it was too hard. He still wants to go but without suffering. It was too difficult," she said on Tuesday.

Medjeberg said she did not know if the doctors would resort to "deep sedation that could lead to a coma which could be irreversible or send him back home with a mobile unit for palliative care".

The main hospital in the northeastern city of Dijon, where Cocq has been admitted, was not immediately available for comment.

Medjeberg said Cocq was delirious, foaming at the mouth and had blood in his stool. He has had nine operations in four years.

Cocq had written to Macron asking to be given a substance that would allow him to die in peace but the president wrote back to him explaining this was not allowed under French law.

Cocq has used his plight to draw attention to the situation of terminally ill patients in France who are not allowed to die in line with their wishes.

"Because I am not above the law, I am not able to comply with your request," Macron said in a letter to Cocq, which the patient published on his Facebook page.

"I cannot ask anyone to go beyond our current legal framework... Your wish is to request active assistance in dying which is not currently permitted in our country."

In order to show France the "agony" caused by the law in its current state, Cocq planned to broadcast the end of his life -- which he believed would come in "four to five days" -- on his Facebook page

Cocq said he has been in a "terminal phase" for 34 years.