Collis gastroplasty is a technique for lengthening a "shortened" esophagus, a condition that often results from gastroesophageal reflux disease (GERD). The stomach acid that flows back into the esophagus in GERD causes tissue changes, inflammation and scarring that can sometimes shorten the esophageal size. In collis gastroplasty, part of your stomach is used to lengthen your esophagus. This lengthening may prevent GERD complications and decrease the risk associated with future reflux-related procedures.