Tracings of concurrent oesophageal manometry, pH, and impedance. Tracings of concurrent oesophageal manometry, pH, and impedance. Example of a “cough-reflux-cough” sequence. The patient used the event marker in the data logger after an acid reflux event, suggesting a “reflux-cough” episode. However, manometry showed a previous cough event that precipitated acid reflux. D Sifrim et al. Gut 2005;54:449-454 Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.