[The crural diaphragm belongs to the pharyngeo-cardial continence organ (PET-CT and impedance measurements on the stretch sphincter and its fixation in the hiatus oesophageus of the diaphragm)].

This paper provides evidence that pharyngeo-cardial propulsion in the oesophagus follows similar principles as translocation of luminal contents in other locations in the body. In brief, the following statements are discussed in the paper: 1. Only animals with a lung-based respiratory system have an oesophagus. 2. Its bulky muscular wall is made up of the elastic fibres which ensure that the oesophagus stays elastic during an entire lifetime. 3. While short-segment ring sphincter systems exist in several locations in the body, the lower oesophageal sphincter is maximally elongated. This configuration helps with the propulsion of luminal contents in addition to this sphincter's opening and occlusive functions. 4. The musculature of the diaphragm is genetically related to the cervical muscles. The crural portion of the diaphragm works in coordination with the lower oesophageal stretch sphincter. 5. Gastro-oesophageal reflux disease is fairly common. In patients with this disorder, the oesophagus is too short and the stretch sphincter remains patent for abnormal periods of time. 6. When the stretch sphincter is surgically retightened by transposition of the oesophageal cardia into the abdomen, a proper function of the regulatory lower oesophageal stretch sphincter can be restored. 7.-9. All fundoplication procedures place the lower oesophageal sphincter under stretch, squeeze and create an oesophageal wrap out of gastric fundus tissue. X-ray images confirm in many patients undergoing fundoplication that the anatomic stretch sphincter already starts above and proximally to the plicated cuff.