New figures show that the number of people waiting more than three months for a bowel cancer check has increased by 13% since May.
The Irish Cancer Society says it is concerned that there are now 1,073 people waiting for a colonoscopy, with 36 patients waiting a year or more for the test.
The ICS says there are enough places for every patient waiting to be seen immediately for free using the National Treatment Purchase Fund and it has urged hospitals to cooperate with the scheme.
Of the 1,073 patients waiting for a colonoscopy, 818 are waiting three to six months, 219 are waiting six months to a year, while the remaining 36 are waiting at least a year.
Bowel cancer is the second most common cause of cancer death, after lung cancer.
In 2008, there were 2,216 new cases diagnosed and 966 deaths.
The HSE said it now conducts a weekly audit of urgent patients awaiting colonoscopy examination to reduce the wait times for urgent cases.
In October 2009, 363 people were waiting longer than the four- week target for urgent referrals.
The HSE said this figure had reduced month-on-month and in May of this year there were 44 patients waiting more than four weeks.
While more recent information is still being validated from across the hospital system, the HSE said indications are that the numbers waiting have continued to fall since May of this year.
Measures to ensure greater efficiency are continuing with the aim of further reducing waiting times for both urgent and non-urgent patients.
