A woman's treatment for terminal bowel cancer was delayed for years due to "a number of oversights" from her GP, the Health and Disability Commissioner has found. 

For more than two years the woman in her 30s – who had a complex medical history - had presented to her medical centre with symptoms including abdominal pain, bowel issues and significant weight loss. 

In a report released today, New Zealand's health system watchdog the Health and Disability Commissioner (HDC) found that the GP had failed to recognise the woman's symptoms over a number of years, which delayed her cancer diagnosis and treatment. 

Due to her young age the GP did not consider her a cancer risk and instead attributed her symptoms to onset inflammatory bowel disease. 

Deputy Health and Disability Commissioner Dr Vanessa Caldwell said a number of failures from the GP had amounted to poor overall care for the patient. 

"In my opinion, a number of oversight's in the GP's care contributed to a delay in the woman's diagnosis of bowel cancer, this delaying her treatment," she said. 

"I do acknowledge the complexity and chronicity of the woman's medical conditions was a difficult background on which to provide care and diagnosis, and I have taken this into account." 

She said the GP had missed multiple opportunities in 2016 and 2017 to follow up on stool and blood tests and make a referral for an endoscopy. 

The GP should also have recognised unexplained iron deficiencies and examine the woman's abdomen, and ordered repeat blood tests to rule out progressive iron deficiency. 

The woman presented to the medical centre in January 2018 with tailbone pain and a different GP found a rectal mass. 

She underwent chemotherapy, surgery and palliative chemotherapy and radiotherapy, but passed away in 2019. 

Caldwell found the GP had breached the Code of Health and Disability Services Consumers' Rights. However, she found the GP's errors were "individual" and the medical centre had not breached the code. 

The report highlights that follow-up tests and appointments were essential for "timely diagnosis". 

Caldwell recommended the GP review cognitive factors in diagnosis from the Royal Australian College of Physicians, and report back to the HDC on his reflections. 

The GP was also asked to write a written apology to the woman's family.