The Clinical Director of Our Lady's Children's Hospital says there is no immediate risk to the 18 children involved in a contamination scare.
His comments come after a bug was found on a colonoscope which was used on 18 children between the 17th of May and the 5th of July.
The parents of 15 out of the 18 children have been contacted - and the hospital hopes to make contact with the remaining three families today.
The problem came to light after a crack was found in a colonoscope that was used during procedures on children between the 17th of May and the 5th of July.
Tests on the equipment found the presence of a bug in a crack in the damaged scope.
The hospital says an information pack and a sample kit to test for the bug is being sent to each of the affected families.
It says results will be returned immediately - and full support given to any family whose child tests positive.
The hospital has apologised for the incident.
Colm Costigan says the bug is not an infection - but it may "colonise" if the children test positive:
