More than 1,000 patients living in fear of having bowel cancer are waiting more than 12 weeks for a colonoscopy, it has emerged.

The Irish Cancer Society said another 219 people were left for six months for the most effective procedure in diagnosing the killer disease - with 36 not seen for more than a year.

That data, calculated by the National Treatment Purchase Fund (NTPF) which manages public hospital waiting lists, showed a steady increase in waiting list numbers since December.

Joan Kelly, nursing services manager with the Irish Cancer Society, urged patients waiting longer than six weeks for a colonoscopy to contact their GP.

"If patients are waiting for longer than three months, it's important to know that you can contact the NTPF to discuss referral for a colonoscopy to a private hospital free of charge," she said.

"If you are concerned about bowel cancer, you can also speak in confidence with a specialist cancer nurse by calling the Irish Cancer Society's National Cancer Helpline."

Bowel cancer is the second most common cause of cancer death in Ireland, after lung cancer.

There were 2,216 new cases in 2008 and 966 deaths from the disease.

More than 50% of patients in Ireland are diagnosed with stage three or four bowel cancer - the most advanced stage. Fewer than 5% of those with stage four survive for longer than five years.

Fine Gael Senator Frances Fitzgerald branded the figures "extremely serious".