Comparison of oesophageal function in patients with acid and non-acid reflux

Background: Decreased oesophageal motility has been described in patients with GastroOesophageal Reflux Disease (GORD); however it is not clear if this impairment is consequence or cause of increased acid exposure. It is known that non-acid reflux causes symptoms. Non-acid reflux may contain pancreatic enzymes and bile that can also be injurious to the oesophageal motility. Therefore the aim of the present study was to investigate the oesophageal motility of patients with symptomatic reflux that is attributed predominately to non-acid reflux and to compare them with patients with symptomatic acid reflux. Patients and methods: Forty-seven symptomatic patients (age: 43(18 – 73)years; male 18; female: 29) were referred for 24h MII-pH and oesophageal motility testing with suspected GORD or who were refractory to double dose PPI treatment. Each patient underwent upper gastrointestinal endoscopy. Water perfusion oesophageal manometry and combined multichannel intraluminal impedance pH-metry were performed in each person after overnight fasting. Non-acid refluxers were defined by having positive symptom correlation predominantly due to non-acid reflux events with positive Symptom Association Probability (SAP) or positive Symptom Index (SI) without positive acid reflux indices of abnormal % time pH< 4, or positive DeMeester score. Acid refluxers were defined by either having positive reflux indices and/or predominately positive symptom correlation with positive SAP or positive SI with acid reflux events. Results: Forty-five per cent (21/47) patients had non-acid reflux and 55% (26/47) were acid refluxers. Oesophagitis was seen in 7 of the 26 acid refluxers but none in the non-acid refluxer group. Only 1 patient out of 21 of non-acid refluxers, whereas 42% (11/26) of the acid refluxers were diagnosed as having ineffective oesophageal motility, notwithstanding that there were no significant differences between the two groups with respect to peristalsis, lower oesophageal pressures, duration of relaxation, complete bolus transit, distal oesophageal amplitude and velocity. Conclusions: Oesophageal motility of patients with non-acid reflux is predominately normal, while ineffective oesophageal motility is frequently diagnosed in acid reflux. This information on oesophageal function in these patients may be useful when evaluating persistent symptoms and selecting treatment, especially antireflux surgery.