NASHVILLE, Tenn. -- If you've had a colonoscopy at the Veterans Administration Hospital in Murfreesboro, you may be at risk of infection from the equipment they used.

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The hospital has known of a potential problem since Dec. 1 but just Wednesday confirmed that it is investigating.

The York Medical Center said it became aware 30 days ago that there was a "potential infection threat" to veterans from "specific colonoscopy equipment used" at the Murfreesboro VA Medical Center.

What sort of threat, what was wrong with the equipment and how many people might be at risk, they won't say.

But doctors agree clean instruments and infection control in colonoscopy are vital because it's such an invasive procedure.

In its memo to Channel 4, the VA said, "Any affected veterans will be notified and screened ... should the result of the clinical review identify a risk."

It seems no letters or phone calls have gone out yet to the patients who need to know.

On Wednesday, the VA spokesman Chris Conklin would not say how long this in-house review might take.

If you've had a colonoscopy procedure at the Alvin York VA Hospital, you may be getting a letter or phone call, but it's unknown when.