Certified Wound Ostomy Nurse (CWON) Practice Test

What is a major factor that prevents a fistula from closing?

1. Low volume output

2. Short fistula tract

3. Previous radiation

4. Minor bowel wall defects

The correct answer is: Previous radiation

A significant factor that contributes to the persistence of a fistula is prior radiation treatment. Radiation can lead to tissue damage and changes in the normal healing process. Specifically, radiation may cause tissue fibrosis, resulting in a less favorable environment for wound healing and closure. The treated tissue often has reduced blood supply and altered cellular responses, which complicates the natural healing mechanisms necessary for a fistula to close effectively. In contrast, other factors like low volume output, short fistula tracts, or minor bowel wall defects do not play as critical a role in preventing closure. Low output can sometimes indicate that a fistula is less active, which may actually support closure. A short fistula tract may provide an easier path for closure compared to longer, more complex tracts. Minor defects in the bowel wall may not significantly impede healing in the same way that the effects of prior radiation would, as they do not typically create the same level of disruption to blood flow and tissue integrity.