What can cause severe pain both in upper part of stomach accompanied with severe back pain?

Gallbladder, gastrit: Severe abdominal pain can refer to the back, so any cause for abdominal pain: gallstones and indigestion are common causes. Avoiding alcohol, stimulants, caffeine, fatty foods and acidic foods could help both these conditions. The gallbladder commonly hurts in the right shoulder/upper back. It occurs after a meal. Indigestion sometimes happens getting into bed, or after a heavy meal.