The WA coroner says doctors failed to properly check blood test results of a man who died at Fiona Stanley Hospital (FSH).

Jared Olsen died in March 2015, weeks after being given the drug 6-mercaptopurine (6-MP) to treat his inflammatory bowel disease (IBD).

6-MP has known side effects including bone marrow toxicity, so standards require patients prescribed with the drug to undergo screening tests for the enzyme TPMT, which help metabolise the drug.

When Mr Olsen was admitted, doctors ordered a TPMT screen, but the hospital's electronic database reportedly generated the request for the test under the name of an intern on Mr Olsen's treatment team.

While the test did show Mr Olsen had severely low levels of TPMT, the results went unnoticed by the treating clinicians when they were released through the electronic system.

WA Coroner Ros Fogliani has found that the death was the result of systemic failures at FSH, but did not make any adverse comments against specific clinicians.

She did find that if doctors had been aware of Mr Olsen's TPMT levels even after he was prescribed 6-MP, his subsequent issues could have been reversible.

Ms Fogliani said FSH needed more robust systems for tracking test results of discharged patients, to make sure results are provided to the relevant consultants.

She also recommended new protocols for highlighting urgent and abnormal test results.

Ms Fogilani suggested similar measures could be adopted across the public health system.

Fiona Stanley Hospital says it has already implemented significant changes to clinical practices.

It is also reviewing the detailed recommendations to address problems with its processes.

The hospital says it is “strongly committed to delivering safe and high quality care to our patients”.