The wallet-sized card threatens legal action against any doctor who seeks to withdraw food or fluid to end the carrier's life.

BBC: Right to die: the reaction

It said it was likely that the provision of food and fluid to Mr O was "not as good as it could have been".

BBC: Cefn Coed Hospital, Swansea apology for patient failure

The patients like them, they are a safe foodstuff and they improve the patients food and fluid intake so it really makes sense to give them a try.

BBC: RELATED BBC SITES

That in turn increases both the amount of fluid and the movement of food in the intestine, helping it function better.

FORBES: Brains Over Guts

The amount of food your stomach will hold is controlled by injecting or removing fluid from the band.

CNN: Surgery helps woman drop 135 pounds, 10 dress sizes