THE parents of a mentally ill man who was allegedly denied food and water and forced to defecate in a cardboard tray while locked in isolation in a public hospital have taken action in the Supreme Court to wrest back control of their son's medical care.

The Scoresby couple wants the court to prevent their 33-year-old son, who they believe has been wrongly diagnosed with schizophrenia, from being transferred back to the Maroondah Hospital at Ringwood from The Alfred, where he is being treated.

The man's parents — who have been feuding with mental health authorities since their son's diagnosis in 1996 — want to care for him at home. —

They say his human and legal rights were violated and his life put at risk earlier this year by staff at Maroondah Hospital.

In an affidavit filed in the Supreme Court, the father of G — who the state's public advocate, Colleen Pearce, has asked not be named for privacy reasons — said his son, who had been living at home, went to Maroondah Hospital's emergency department on January 5 because he felt dehydrated and anxious.

G's father said his son was certified and incarcerated in the high-dependency isolation ward within minutes of seeing a psychiatrist and without any consultation with the family.

G's treatment over the next few weeks, according to his father, endangered his life.

"G was stripped of all dignity and forced by medical and nursing staff to defecate in a tray," G's father said in his affidavit.

"Forced to urinate in a bottle. Forced to eat in the same room as having just relieved his bowels.

"G spent three weeks in solitary seclusion without being allowed to have a shower, wash his hands … and was subject to a very serious health risk."

G's father said he had to shout through a thick glass door to his son during access visits.

And he claimed that on January 28, G was denied food or water between 8.30am and 2.40pm because he had not obeyed nurses' orders.

Eastern Health denies mistreating G. "Eastern Health treats all its patients in its mental health service with the highest standards and in accordance with the Mental Health Act," spokesman Ben Kelly told The Sunday Age.

"Our priority is to treat patients at the highest standard of care with dignity and respect and to make every effort to improve their wellbeing."

G's father claims his son's mental health problems have been caused by the anti-psychotic drugs, including the controversial Zyprexa, that he has been prescribed since he first went to Maroondah Hospital in 1996 complaining of a cannabis-induced headache.

G's latest admission to hospital, on August 7, followed a successful period of living at home and reporting to the Maroondah Hospital at 9.30am and 3pm each day for his medication — a treatment plan approved by the Mental Health Review Board in June.

After feeling ill, G admitted himself to Maroondah Hospital, where he was placed in seclusion for three weeks before being sent to The Alfred a fortnight ago.

G's father says he now fears he will be returned to Maroondah.

He says he took the Supreme Court action in May because he was outraged over a decision by the state's chief psychiatrist that G should return to hospital care. He says he wants a court ruling that would ensure G is never again put under the care of staff at Maroondah Hospital.

When asked how G was coping, his father said: "His comment when coming out of sedation was: 'Dad, they can't keep doing this to me … please Dad, no more'."