The mother of a critically-ill boy has told his inquest she placed "trust in that doctor" who discharged her son from hospital less than 24 hours before his death.

Callum Cartlidge, described as a friendly, smiley child, died after suffering a cardiac arrest at his home in Redditch, on March 3, 2017.

The eight-year-old had been discharged from hospital with a diagnosis of gastroentiritis, the day before, Worcestershire Coroner's Court heard on Wednesday.

Callum suffered an undiagnosed adrenal Addisonian crisis linked to the rare condition Addison’s Disease, hours after being sent home from Worcestershire Royal Hospital with “Dioralyte”.

The day he died, paramedics had to drive Callum the 23 minutes to Worcestershire Royal Hospital, Worcester, despite Redditch Alexandra Hospital being three minutes away.

However, the clinical director of paediatrics told assistant coroner David Reid "the outcome would not have been any different" for Callum, had the Alex been equipped to take him.

Worcestershire Acute Hospitals NHS Foundation Trust decided in September 2016 to focus all paediatric care for seriously ill under-16s at its main Worcester site.

Callum had been diagnosed with gastro-entiritis after his emergency admission to the Worcester hospital, but was later allowed home with his parents.

His mother said despite that diagnosis by registrar Dr Ann Radcliffe, her son remained "unwell".

Stacey Cartlidge told the coroner: "I wasn't happy.

"He just didn't look like Callum. He was quiet.

"We had to put his onesie on.

"I kept saying 'are you ok?' and he'd say 'yeah' but you knew he wasn't.

"I kept asking Dr Radcliffe if he was ok to go home, and she said he was.

"I put my trust in that doctor."

A trainee junior doctor had noted for senior colleagues to "consider bloods", and it was accepted by Dr Radcliffe on Tuesday such a test would have had a "high chance" of uncovering the boy's rare illness.

However, she said his "clinical presentation" led to her actual diagnosis - and a senior colleague backed her finding on Wednesday, calling it "appropriate".

A post-mortem examination found evidence of viral gastro-entiritis, as well as his undiagnosed "extremely rare" condition.

The inquest has heard how despite Callum being dehydrated, the ward sister at the hospital's Riverbank children's unit failed to fill in a fluid monitoring chart.

Dr Baylon Kamalarajan, the hospital's clinical director of paediatrics, said that failure had led to routine auditing of patient paperwork at the hospital.

Asked by the coroner if Callum's outcome might have been altered, the consultant replied: "I think the answer is no.

"We know the outcome in out-of-hospital cardiac arrests is poor, with less than two per cent survival rate.

He added: "I can be as certain as I can be the outcome would not have been any different, whether they (the paramedics) went to the Alexandra Hospital or the Worcestershire Royal."

He told the coroner the level of acidosis in Callum's blood was "not compatible with life", on arrival at Worcester.

The consultant of 18 years experience, said Dr Radcliffe's diagnosis and discharge were "appropriate" given his "clinical presentation".

Callum, suffered a fatal collapse at about 3.30pm at his Redditch home.

Paramedics double-checked whether they could take Callum to the Alexandra Hospital.

Reading from the service's official post-incident report, Mr Reid said: "It was confirmed by the (Alexandra) hospital they are not equipped to deal with a patient and they should be transferred to Worcestershire Royal Hospital."

The was taken to Worcester, but was confirmed dead despite the efforts of A&E staff at 4.35pm.

The trust said at the time of the 2016 decision it was down to a shortage of qualified doctors, and maintaining patient safety.

Mr Reid also said: "It is clear Callum fulfilled the criteria to be taken to the Worcestershire Royal Hospital, or another appropriate emergency department."

The coroner said cause of death was given as Addisonian crisis caused by autoimmune adrenalitis - causing "chronic wasting" of his adrenal glands, contributed to by gastoentiritis.

The inquest continues.