Scientists solve long-debated puzzle of how the intestine heals itself. Scientists find that normal intestinal cells 'de-differentiate' en masse into stem cells that generate the cells needed for a healthy intestinal lining. New study establishes de-differentiation as the predominant mode of stem cell recover in the intestine. Source 5v.
As the article says, cells in the body constantly die and new ones replaces them. So technically in a way perhaps the same concept could apply to even organs - where some cells die out of external issues but they get replaced overtime. Though, despite this perhaps medical conditions, decreased health and age can affect this.