| Theme |
GERD -- Recent Clinical Advances |
| Title |
Mechanisms of Acid Reflux in Healthy Subjects and Patients with Reflux Esophagitis |
| Author |
Katsuhiko Iwakiri |
Department of Gastroenterology, Nippon Medical School |
| Author |
Noriyuki Kawami |
Department of Gastroenterology, Nippon Medical School |
| Author |
Hirohito Sano |
Department of Gastroenterology, Nippon Medical School |
| Author |
Yuriko Tanaka |
Department of Gastroenterology, Nippon Medical School |
| Author |
Mariko Umesawa |
Department of Gastroenterology, Nippon Medical School |
| Author |
Makoto Kotoyori |
Department of Gastroenterology, Nippon Medical School |
| Author |
Yoshio Hoshihara |
Department of Gastroenterology, Nippon Medical School |
| Author |
Chouitsu Sakamoto |
Department of Gastroenterology, Nippon Medical School |
| [ Summary ] |
Transient lower esophageal sphincter relaxation(TLESR),i.e. lower esophageal sphincter(LES) relaxation not induced by swallowing, is the major mechanism underlying acid reflux both in healthy subjects and in patients with reflux esophagitis(RE). Our study on the mechanisms underlying acid reflux showed that nearly 100% of acid reflux episodes are associated with TLESRs in healthy subjects and patients with mild RE. In patients with severe RE, TLESRs are also the most important mechanism associated with acid reflux episodes. Approximately 80% (median) of acid reflux episodes are related to TLESRs.
Even though TLESRs are the major mechanism causing acid reflux episodes, low LES pressure is also an important mechanism. In the presence of low LES pressure, acid reflux is thought to occur either with free flows from the stomach into the esophagus (free reflux) or during periods of abdominal strain (strain reflux). Prolonged monitoring of patterns of LES pressure has shown that defective basal LES pressure is responsible for only a small number of acid reflux episodes. This mechanism appears to be confined mostly to patients with severe RE. |