A narrowing or obstruction of the esophagus (the tube that connects the throat and stomach) that may lead to dysphagia. Esophageal stricture occurs as a result of the accumulation of scar tissue in the esophagus, as in persistent esophageal reflux. Scarring and narrowing can also be due to prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs), the antibiotic tetracycline, or potassium supplements.