• gastro-oesophageal reflux disease
• anti-reflux surgery
• ambulatory ph monitoring

The typical symptoms of gastro-oesophageal reflux disease (GERD) are heartburn and regurgitation. Given such prominence, you might assume the two symptoms to be on equal footing, but that is far from true. Rather, heartburn dominates, and regurgitation is usually an afterthought. Whereas there are a multitude of instruments for gauging the severity of heartburn in clinical trials and proclaiming the therapeutic efficacy of therapies, there are essentially none for regurgitation. In fact, the first clinical trial in GERD to use improvement in regurgitation as the primary outcome was the RESPECT study comparing the efficacy of transoral incisionless fundoplication plus placebo to a sham procedure plus omeprazole in patients with regurgitation-dominant reflux disease published in 2015.1 That was also the first clinical trial in which a surgical procedure for GERD was found superior to adequately dosed proton pump inhibitors (PPIs). That outcome was, to some degree, predictable given that regurgitation is not that effectively treated by PPIs.2 The surprise is that it took so long to recognise regurgitation as the Achilles heel of PPI therapy for GERD.

Using regurgitation as an outcome measure in clinical trials has challenges, perhaps explaining why it is rarely done. One challenge is the lack of a common understanding of what the word …