Dr Schultz was reported in yesterday's Otago Daily Times saying a Central Otago and Queenstown Lakes charity initiative found it hard to fill the 30 available spots.
The programme was funded by the Central Otago Pinot Noir Charitable Trust and Mercy Hospital's Charitable Outreach programme.
Dr Schultz, the Dunedin-based doctor who will carry out the procedures, said he could not explain the official figures, of which he was unaware until contacted by the ODT.
He suggested a perception lingered from previous overloading of the gastroenterology service, which deterred GPs from referring patients.
''The perception out there is that you still can't get colonoscopies, which is hard to understand, to a certain degree.''
Dr Schultz had had letters from GPs saying they would not refer a particular patient for a colonoscopy because of difficulties accessing the service, when the details of the patient's case clearly warranted referral.
The figures were presented to a Southern District Health Board committee in Invercargill last week.
In May, the most recent figures available, 65% of urgent colonoscopies were performed on time (two weeks), 27% of routine colonoscopies were performed on time (six weeks), and 53% of surveillance colonoscopies were performed within the target of 12 weeks.
Wait times for urgent and surveillance procedures had improved from the previous month, while routine waiting times had worsened slightly.
Extra funding from the Ministry of Health had recently allowed the board to complete an extra 185 procedures.
Improvement in routine and surveillance waiting times were expected in the next three months, a report to the committee said.
Central Otago patients were on the same waiting list as Dunedin patients, so waiting times would be consistent in outlying areas and the city.
Queenstown Lakes patients fell into the Southland Hospital catchment.
While wait times were likely to be longer in Southland Hospital than in Dunedin, Dr Schultz had not noticed greater interest in the programme from people in Queenstown Lakes.
Health board gastroenterology clinical leader Jason Hill said in an emailed statement the gastroenterology team used nationally recommended criteria for service access.
''An additional 185 colonoscopies have been completed by 30 June as a result of additional funding from the Ministry of Health.
"This funding will result in a decrease in the number of colonoscopies waiting for extended periods of time.''
The board did not respond to a request for a breakdown of wait times showing Otago and Southland individually.