Two Cases of Diagnosis and Botulinum Toxin Treatment in Patients Who Were Unable to Burp

Retrograde cricopharyngeus dysfunction (R-CPD) is a new syndrome first described in 2019 by Bastian. It is characterized by an inability to belch, along with associated symptoms such as loud gurgling noises, chest and abdominal pain/distention, and excessive flatulence. The cause of R-CPD is not yet clearly understood, but it is believed to be related to the dysfunction of the cricopharyngeus muscle. In Korea, R-CPD is not well understood yet and consequently, there is no available treatment for this condition to date. Here, we aim to report two cases of diagnosing and treating patients with R-CPD for the first time in Korea using botulinum toxin injection under local anesthesia.