study verified the feasibility and usefulness of 5% sodium thiosulfate solution (STS). 2 This multicenter, randomized, double-blind study initially compared normal saline solution (NS), STS, and 2% VCS after spraying Lugol iodine solution to evaluate the acute and late adverse symptoms and the discoloration effect on esophageal mucosa stained brown by iodine. The authors reported that both VCS and STS similarly decreased the severity scores of the acute adverse symptoms in comparison with spraying NS, and VCS remarkably alleviated acute acid regurgitation or heartburn and late retrosternal discomfort or pain compared with STS. Furthermore, VCS and STS did better in fading iodine dye than did NS.Jin et al 1 enrolled 240 patients, among whom 50 patients (20.8%) underwent routine upper endoscopy, and 233 study participants had not received diagnoses of esophageal dysplasia or carcinoma. Lugol iodine staining is routinely recommended for patients at high risk for esophageal dysplasia and carcinoma. Because patients with esophageal dysplasia and carcinoma may have different symptoms from those without, we were puzzled whether their results are applicable to patients suspected of having esophageal dysplasia and carcinoma; they mainly enrolled patients who did not need Lugol iodine staining. In addition, the questionnaire on the adverse symptoms of iodine staining should be completed before endoscopic examination to ensure that patients are free of those symptoms before endoscopy. It would be better if the authors could make a connection between symptoms and the discoloration effect. We recommend that endoscopic examination time, which may be related to abdominal pain and the type of insufflation gas (air or CO 2 ), should be added in their study.We truly believe that VCS should be further tested in patients at high risk for esophageal carcinoma.