The Irish Cancer Society has said there has been a significant improvement in waiting times for a colonoscopy in the past two months.
The procedure is the most effective way of diagnosing bowel cancer.
Concern was raised about the number patients waiting six months or more for the test last November.
This number has more than halved since then.
However, figures from the National Treatment Purchase Fund show that 435 patients around the country are still waiting six months or more.