V ARIOUS operations have been devised for the surgical treatment of reflux esophagitis associated with hiatus hernia. (Belsey1 has designed an operation in which the fundus of the stomach is wrapped around the distal esophagus.) Our studies on the mechanisms of the gastroesophageal sphincter in normal subjects and in patients with hiatus hernia suggested that the principle of this operation would lead to reconstitution of a normal sphincter mechanism at the gastroesophageal junction. This hypothesis was tested by studying the pressure characteristics of this region, before and after repair. There have been previous studies on the pressure characteristics of this region in hiatus hernia.2-4 Our study demonstrated that hiatus hernia could be classified into two groups.4 In one group, the maximum pressure in the gastroesophageal sphincter was within normal limits and there was a normal sphincteric response to abdominal compression. These patients did not have endoscopic evidence