Patients who cannot eat have told BBC News they are petrified and fear for their lives after problems making their replacement nutrition.
They are completely dependent on bags filled with a liquid that contains everything their body needs and is infused into their hearts.
The NHS in England has described the issue as a national emergency.
“My life is in a lot of danger right now,” Lauren Mitchell, 21, from Stansted, Essex, told BBC News.
She was born with chronic intestinal pseudo-obstruction.
It means the muscles that should push food round her digestive system do not work and her meals would just sit on her stomach.
Lauren has been kept alive by total parenteral nutrition (TPN) since she was seven years old.
It was manufactured by the company Calea