Dunedin Hospital is exploring how it can increase its elective colonoscopies as it struggles to meet an "ambitious target".
It is expected to deliver 800 elective colonoscopies this financial year but, with seven months of the year gone, only 383 have been carried out .
It was reported to the board's hospitals' advisory committee this month that, by the end of December, the number was already 68 below the planned number.
Board emergency medicine and surgery general manager Dr Colleen Coop said the target number, which was similar to that achieved last year, was "ambitious to begin with".
Last year, it had been met only because a specialist agreed to do extra work at weekends.
This year, the number of procedures had been affected by specialists, who had been working extra hours, reverting to their contracted hours.
Nursing turnover was also having an impact.
The board hopes it may have a long-term locum gastroenterologist by June.
There have been long-standing vacancies amounting to 1.3 full-time equivalent (FTE) vacancies in the department.
Some of the alternatives which may be explored by the board include looking at the possibility of patients travelling to Invercargill, the use of colonography and whether there is capacity in the private sector.
Colonography, a less invasive procedure involving CT scanning, is not offered at Dunedin Hospital but is available in Invercargill.
Some doctors are critical of this procedure because of its purely diagnostic nature.
Patients found to have polyps through a colonography would still have to undergo a colonoscopy to remove them.
With a colonoscopy, cancers can be detected along with pre-cancerous polyps.
The latter can be removed during the procedure.
