A small, digestive organ positioned under the liver, which concentrates and stores bile. Problems with the gallbladder often lead to “gallbladder attacks”, which usually occur after a fatty meal and at night. The following are the most common symptoms: steady, severe pain in the middle-upper abdomen or below the ribs on the right; pain in the back between the shoulder blades; pain under the right shoulder; nausea; vomiting; fever; chills; jaundice; abdominal bloating; intolerance of fatty foods; belching or gas; indigestion.