food enters the stomach by passing through the muscular
Food enters the stomach through esophagus after passing through a muscular valve called the lower esophageal sphincter. In other words the LES is a ring of muscle at the bottom of the esophagus that acts like a valve between the esophagus and stomach.The sphincter relaxes during swallowing to allow food to pass. Full Story. What is stomach Acid Reflux (GERD). Stomach Reflux is a condition in which the lower esophageal sphincter (LES) (the muscular ring at the lower end of the esophagus) is abnormally relaxed and allowing the stomach corrosive contents to back up or 'reflux' into the gullet (esophagus).