A Lincoln grandmother's doubts about the surgeon lined up to fix her sore back ended up costing her almost $20,000.

Liz Patterson, 75, had been waiting five months to make it to the top of the Canterbury District Health Board's (CDHB) waiting list for back surgery, but said she was dropped back to the bottom after asking to switch to another surgeon.

Patterson began suffering back pain several years ago.

"I couldn't sleep, I couldn't bend. It got so bad that I couldn't drive the car any more."

She was told she needed a laminectomy - a type of orthopaedic surgery - but in December 2011 her GP recommended she see a particular neurosurgeon at Christchurch Hospital.

She was put on the doctor's public waiting list in July 2012, but later paid for a second opinion from an orthopaedic surgeon because she felt uncomfortable having the neurosurgeon carry out the procedure.

Patterson had a botched operation about 10 years ago, when a surgeon mistakenly removed part of her bowel.

"I'd already had a medical misadventure and I was terrified of it happening again."

She decided to go with the second surgeon in November 2012, but was told she would have to start at the bottom of the list because she had changed specialists.

Her GP wrote a letter to the CDHB stating the surgery was needed urgently, but it was not taken into consideration, she said.

"I waited all this time and thought I was entitled to have it done. Everybody's entitled to a second opinion, but if you change doctors you have to go to the bottom of that doctor's waiting list, regardless of your doctor's opinion or your family situation."

Her husband, Ernie, 75, was diagnosed with terminal cancer earlier that year and Patterson said she had needed surgery as soon as possible so she could look after him.

She used almost $20,000 from her retirement savings to have the operation done privately in December and was left feeling disillusioned with the public health system. She planned to complain to the Health and Disability Commissioner but had not complained to the CDHB because she did not believe her complaint would be taken seriously.

"I'm not going to go away, not this time," she said. "I want to make sure it doesn't happen to anyone else."

A CDHB spokeswoman could not comment on Patterson's case, but said different specialists had different waiting lists and there were different criteria for each list.

A patient was entitled to seek other opinions and change doctors, but could not expect to go straight to the top of that doctor's public waiting list ahead of other patients who could be in more need.

Christchurch surgeon and Charity Hospital founder Philip Bagshaw said the case highlighted the need for patients to sort out any doubts they had as soon as possible.

It was also "good practice" for health professionals to recommend patients get a second opinion before they committed to surgery, he said.

- © Fairfax NZ News