Introduction
‘Inability to Belch’, also called retrograde cricopharyngeal dysfunction (R-CPD), is a syndrome characterized by inability or impaired ability to belch, gurgling noises from the chest or lower neck, thoracic or abdominal pain, bloating and flatulence (1). Although awareness of the disorder is increasing, little is known about its cause, characteristics or epidemiology.
Besides recognition of typical symptoms, high resolution impedance manometry (HRiM) is increasingly used to confirm the diagnosis in suspected cases (2, 3).
Aims & Methods
Our aim was to design a diagnostic questionnaire based on the cardinal symptoms, and to validate this questionnaire against the only available objective diagnostic tool at present, i.e. HRiM with belch provocation test (sparkling water) (2, 3).
The questionnaire was developed based on medical history taking of patients that presented to our center with ‘inability to belch’ (4). Fifteen symptoms were included: inability to belch, gurgling noises, thoracic pain, abdominal pain, nausea, fullness, early satiety, bloating, flatulence, heartburn, regurgitation, frequent or painful hiccups, dysphagia, and difficulty to vomit. These were questioned for frequency, severity, bothersomeness and the trigger or timing at which they occurred. A first draft of the questionnaire was evaluated in a cognitive debriefing of the first three R-CPD patients, after which some clarifying changes were made.
Subsequently, the questionnaire was filled out during HRiM prospectively by R-CPD and control patients, each of whom underwent belch provocation test as described by our group (3).
Wilcoxon signed rank test was used to compare between groups. A logistic model was used to compute probabilities with their 95% confidence interval (CI).
Results
The questionnaire was completed by 17 patients reporting inability to belch, and 47 control patients, during HRiM with belch provocation test. In 13 out of 17 patients (sensitivity 76%, positive likelihood ratio of HRiM: 8.44), R-CPD was confirmed with typical findings on HRiM. The indication for HRiM in control patients was GERD (n=27), dysphagia (n=9), chest pain (n=3), known achalasia (n=2), belching (n=1), globus (n=1) and dyspepsia (n=1). In the control patient group, 4 patients were excluded from further analysis because of abnormalities on HRiM similar to R-CPD (specificity 91%, negative likelihood ratio: 0.26).
Using HRiM as a gold standard, we identified the following questions that were significantly different in R-CPD patients vs. controls: frequency of inability to belch (p <0.001, probability of abnormal HRiM when present: 0.6000 CI 0.380:0.786 ), gurgling noises (p = 0.0019, probability when present 0.4000, CI 0.230:0.597), and dysphagia (p = 0.003, probability when present 0.065, CI 0.016:0.022). Even though these symptoms were often present in R-CPD, chest pain, abdominal pain, nausea, fullness, early satiety, bloating, heartburn, regurgitation, hiccups and vomiting did not differ significantly between both patient groups.
Conclusion
We designed a diagnostic questionnaire to help identifying R-CPD. Based on a comparison between R-CPD patients with a control population with a variety of upper motility disorders, the presence of ‘inability to belch’, gurgling noises; and the absence of dysphagia were significantly different between R-CPD patients and controls.
Pending further validation, this questionnaire provides a basis for developing a scoring system for patients with ‘inability to belch’ and it can be used to explore the epidemiology of this peculiar syndrome.
References
1. Bastian RW, Smithson ML. Inability to Belch and Associated Symptoms Due to Retrograde Cricopharyngeus Dysfunction: Diagnosis and Treatment. OTO Open. 2019;3(1):2473974x19834553.
2. Oude Nijhuis RAB, Snelleman JA, Oors JM, Kessing BF, Heuveling DA, Schuitenmaker JM, et al. The inability to belch syndrome: A study using concurrent high-resolution manometry and impedance monitoring. Neurogastroenterol Motil. 2022;34(5):e14250.
3. Karlien Raymenants FV, Stijn Arnaert, Jan Tack, Tim Vanuytsel, Filip Baert, Lieve Delsupehe, Joris Arts Manometric diagnosis and treatment of retrograde cricopharyngeus dysfunction (R-CPD). United European Gastroenterology Journal. 2023;11.
4. Arnaert S, Arts J, Raymenants K, Baert F, Delsupehe K. Retrograde Cricopharyngeus Dysfunction, a New Motility Disorder: Single Center Case Series and Treatment Results. J Neurogastroenterol Motil. 2024;30(2):177-83.