Failure of relaxation of the lower esophageal sphincter (also known as the cardiac sphincter) causes an accumulation of food in the esophagus. Achalasia is the failure of motility of food through the esophagus into the stomach. A constricted lower esophageal sphincter is the cause of these conditions. Dyspepsia is chronic pain or discomfort in the upper abdomen. This usually accompanies problems with digestion and is not associated with difficulty swallowing. Gastritis is inflammation of the mucosal lining of the stomach and would also not contribute to dysphagia. Gastroparesis is defined as delayed stomach emptying due to stomach paralysis, which would reveal chyme overloading in the stomach and esophagus (achalasia involves only the esophagus). Peptic ulcers mostly result in pain in the stomach, more commonly the duodenum, due to erosion of the mucosal lining.