Schatzki ring

A Schatzki ring or Schatzki–Gary ring is a narrowing of the lower esophagus that can cause difficulty swallowing (dysphagia). The narrowing is caused by a ring of mucosal tissue (which lines the esophagus) or muscular tissue. A Schatzki ring is a specific type of "esophageal ring", and Schatzki rings are further subdivided into those above the esophagus/stomach junction (A rings), and those found at the squamocolumnar junction in the lower esophagus (B rings).