The esophagus Throat and Esophagus The throat (pharynx) lies behind and below the mouth. When food and fluids leave the mouth, they pass through the throat. Swallowing of food and fluids begins voluntarily and continues automatically... read more is the hollow tube that leads from the throat (pharynx) to the stomach. (See also Overview of Esophageal Obstructions Overview of Esophageal Obstructions The esophagus (the hollow tube that leads from the throat to the stomach) can be narrowed or completely obstructed (blocked). In most cases, the cause is Progression of an injury to the esophagus... read more .)
Some lower esophageal rings may be caused by inflammation of the esophagus due to acid reflux Gastroesophageal Reflux Disease (GERD) In gastroesophageal reflux disease, stomach contents, including acid and bile, flow backward from the stomach into the esophagus, causing inflammation in the esophagus and pain in the bottom... read more 
or pills that are not completely swallowed (erosive esophagitis).
Normally, the lower esophagus has a diameter of about ¾ inch (about 2 centimeters). However, it may be narrowed to ½ inch in diameter (about 1¼ centimeters) or less by a ring of tight tissue, which may cause difficulty in swallowing solids. This symptom can begin at any age but usually does not begin until after age 25. The swallowing difficulty Difficulty Swallowing Some people have difficulty swallowing (dysphagia). In dysphagia, foods and/or liquids do not move normally from the throat (pharynx) to the stomach. People feel as though food or liquids become... read more (dysphagia) comes and goes and is especially aggravated by meat and dry bread.
Often, the ring is found when doctors look down the esophagus with a flexible tube (endoscopy Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). In addition to examinations, doctors can use endoscopy to do biopsies and give treatment. Endoscopes... read more ) to look for reasons why people are having difficulty swallowing. Barium swallow X-Ray Studies of the Digestive Tract X-rays often are used to evaluate digestive problems. Standard x-rays ( plain x-rays) can show some blockages or paralysis of the digestive tract, or abnormal air patterns in the abdominal cavity... read more x-rays also show the ring. In this test, people are given barium in a liquid before x-rays are taken. The barium outlines the esophagus, making abnormalities easier to see.
Chewing food thoroughly followed by taking sips of water usually prevents symptoms. A doctor may fix the narrowing by passing an endoscope through the mouth and throat and into the esophagus or may use a blunt-tipped instrument (called a bougie) to widen the passageway. In rare cases, doctors widen the constricting ring by doing a surgical procedure.
