Functional heartburn vs. non-erosive reflux disease: similarities and differences

Bowel symptoms have been associated with non-erosive reflux disease (NERD). However, their role in functional heartburn (FH) has not been established.

To characterize bowel symptoms in FH and NERD patients, and investigate their role as predictors of severity of reflux symptoms.

A prospective study of patients with normal upper endoscopy undergoing a 24-h oesophageal pH monitoring for the evaluation of reflux symptoms. Patients with oesophageal acid exposure <3.1% and a symptom index <50% were classified as FH (n = 60), while those with oesophageal acid exposure >4% were defined as NERD (n = 160). Symptom severity was scored on validated scales.

In FH, a female predominance was noted (P < 0.001). Reflux symptoms were scored higher in NERD patients (P < 0.001) while bowel symptoms were similarly scored in the two groups. In both groups, severity of reflux symptoms was independently associated with a composite score on the bowel scales (P < 0.001) and was not predicted by oesophageal acid exposure. In FH, reflux symptom severity was inversely related to age (P = 0.03), while in NERD, the opposite was true (P = 0.01).

In both FH and NERD, bowel symptoms were the strongest predictors of reflux symptoms severity. A female preponderance, and an opposite relationship between reflux symptom severity and age, indicate that FH and NERD may be distinct entities.