Doctors told me gastritis can't cause flank area pain or back pain. And now I'm stressing : r Gastritis Gastritis Definition: Inflammation of the gastric mucosa, which may be acute or chronic, commonly due to infection, drugs, or autoimmune causes. Symptoms: * Epigastric pain (burning gnawing) * Nausea, vomiting * Bloating, early Gastritis Beacon Health System How to Know if You Have Gastritis: Symptoms & Diagnosis Differential Diagnosis II: Gastritis Peptic Ulcer Case Study