Gastric emptying and different types of reflux in adult patients with cystic fibrosis

Background Increased gastro-oesophageal reflux (GER) is common in patients with cystic fibrosis (CF). Previous studies showed delayed gastric emptying (GE) and a high prevalence of bile acids in saliva suggesting duodenogastro-oesophageal reflux (DGER). Aim To assess different types of reflux (acid, weakly acidic and bile) and their relationship with rate of GE in adult CF patients. Methods Gastric emptying was assessed in 33 CF patients using breath tests, reflux was monitored in 42 patients using impedance-pH-metry and 14 CF patients underwent combined impedance-pH-Bilitec monitoring. Results Delayed GE was found in 33%, increased GER (predominantly acid) in 67% and pathological DGER in 35% of the CF patients. There was a significant correlation between oesophageal bile and acid exposure (P < 0.0001, r = 0.85). Patients with increased DGER had a higher proximal extent of reflux compared to those without DGER [17 (9-35) vs. 5 (1-12), P = 0.04]. There was no correlation between GE and reflux parameters, however, in a subgroup of 10 patients studied by impedance-pH-Bilitec and GE, there was a strong correlation between GE rate and bile exposure (P = 0.005, r = 0.83). Conclusions Delayed gastric emptying is present in 1/3 of patients with cystic fibrosis. There is a subgroup of these patients with both delayed gastric emptying and increased acidic duodenogastro-oesophageal reflux with high proximal extent and risk of aspiration. Controlled studies should be performed to evaluate the effect of prokinetics or antireflux surgery on the clinical cystic fibrosis evolution in these patients.