WHAT YOU NEED TO KNOW: An esophageal stricture is a narrowing of your esophagus. Inflammation or damage to your esophagus may cause scar tissue that leads to narrowing. 1  Long-term acid reflux. 2  Birth defects, such as stenosis (narrowing) or diverticulosis (pouches)  Medicines, such as aspirin, pain medicines, or antimalarial antibiotics.