A bronchial fistula is an abnormal connection that forms between a bronchus, which is a major airway in the lungs, and another structure, such as the esophagus or the surrounding tissues. This condition can occur due to various reasons, including complications from surgery, infections, or diseases like tuberculosis. Symptoms of a bronchial fistula may include coughing, difficulty breathing, and the presence of food or liquid in the lungs. Diagnosis typically involves imaging studies, such as CT scans, and treatment may require surgical intervention to close the fistula and restore normal airway function.