The previous Labour Government announced a nationwide screening programme to begin in 2009 but this stalled after National came into power.
Mr Ryall said yesterday it was important to collect evidence on whether the programme was cost-effective. This would be known by mid-2016.
One of the issues has been the need for extra staff to perform the higher numbers of colonoscopies which would result from an expanded screening programme.
Nadine Hooper fitted into few of the risk categories when she took her first bowel cancer screening test two years ago.
After the test detected some symptoms, healthcare professionals told the 46 year-old that it was unlikely they were a sign of something sinister.
The mother-of-two from Papamoa said: "Even as I got on the table for the colonoscopy the specialist said 'What are you concerned about?"'
However, the doctor found a single cancerous polyp.
"It totally came out of the blue," Ms Hooper said. "I've got no family history of bowel cancer. I'm female, I'm technically too young to have it."
"I wasn't really on anyone's radar for having bowel cancer."
Ms Hooper, a relief teacher, was now urging friends and family to get tested. She said that in hindsight, she had noticed gradual changes in her body and was lucky that she was tested in time.
She still faced a difficult four-month wait between her initial test and a colonoscopy - a sign of district health boards' struggle to keep up with the demand for examinations.
Patients who opted for a private colonoscopy could expect a bill of around $1400.
Ms Hooper strongly supported a national bowel cancer screening programme, arguing that the increased funding would far outweigh the emotional toll of New Zealand's abnormally high number of bowel cancer cases.
Screening programmes tended to detect cancers at an earlier stage than a normal clinical setting, in which people only visited their doctor once they become aware of physical symptoms.