Table 3

 Characteristics of heartburn and regurgitation

HeartburnRegurgitationp Value
Values are median (interquartile range).
pH drop3.5 (1.9–4.4)2.6 (1.8–4.5)0.7
Nadir pH2.2 (1.8–3.3)2.3 (1.9–3.2)0.7
Proximal extent (cm)11 (9–15)15 (11–18)0.002
Ascending velocity (cm/s)5.0 (3.3–9.2)6.0 (3.2–8.8)0.9
Volume clearance (s)13 (8–21)11 (8–18)0.4
Acid clearance (s)57 (30–120)60 (30–100)0.9