Adverse effects occur in 7.5% of patients who undergo peroral endoscopic myotomy, according to a study of 1,826 patients who underwent the procedure. Details of the investigation are as follows:

• 156 adverse reactions developed in 137 patients.
• 2.5% of patients experienced an inadvertent mucosotomy.
• Mild adverse effects occurred in 6.4% of patients while moderate and severe reactions developed in 1.7% and 0.5%, respectively.
• Adverse effects were associated with several variables, including a sigmoid-type esophagus, the experience of the endoscopist, use of a triangular tip knife, and use of electrosurgical current different than spray coagulation.