Reflux esophagitis can be observed during an endoscopy as changes in the esophageal mucosa, including hyperemia, edema, erosion, and ulcers. The severity is graded based on the size of the erosion and ulcers, with smaller areas indicating milder conditions and larger areas indicating more severe conditions. An endoscopy can definitively diagnose reflux esophagitis, whose main symptoms include upper abdominal pain, chest pain, belching, acid reflux, nausea, and vomiting. The treatment primarily involves acid suppression, protection of the stomach lining, and promoting gastric motility, with a treatment duration of about six to eight weeks. Dietary considerations include avoiding smoking and drinking alcohol, not consuming strong tea or coffee, and avoiding spicy, stimulating, fried, and barbecued foods that are difficult to digest.