What causes pain in esophagus and chest when swallowing? Also excessive need to burp? Thanks currently on lanzoprazole

Odynophagia. Esophageal stenosis (narrowing) from scar tissue (strictures) is of itself not painful. However, depending upon how tightly narrowed the stricture may be, food can impact there (cause dysphagia). Usually dysphagia occurs with meats, bread. Pain on swallowing (odynophagia) may result. Esophageal spasm, dysmotility, ulcers, fungal infection (usually candida) are all possible. Best to get evaluated.