Oesophagitis is inflammation or erosion of the oesophageal lining, most commonly caused by repeated acid reflux from the stomach. The classic symptom is heartburn, a burning sensation behind the breastbone, sometimes with regurgitation, painful swallowing, or chronic cough. Endoscopy grades the damage from mild redness to deep ulceration and Barrett’s oesophagus, a precancerous change from long-standing reflux. Dietary management is first-line alongside medication: weight loss in overweight patients, smaller and earlier evening meals, and reduced intake of fatty foods, chocolate, mint, citrus, tomato, spicy foods, caffeine, and alcohol, all of which can relax the lower oesophageal sphincter or directly irritate the mucosa. Eosinophilic oesophagitis, an allergic form, instead requires identification and elimination of trigger foods, commonly milk, egg, wheat, and soy.