Transient Whitish Change in the Gastric Mucosa Induced by Water-Jet Flushing.

Localized transient whitening of the gastric mucosa after water-jet flushing through the auxiliary water channel is rarely described. We report a 49-year-old man who underwent endoscopic submucosal dissection for a 5-mm gastric-type neoplasm on the greater curvature of the lower gastric body. During washing of adjacent non-lesional mucosa, strong auxiliary water-channel flushing for approximately 2-5 s was followed by a focal whitish linear change confined to the flushed area, which became evident approximately 10 s after flushing was stopped and persisted for approximately 30 s before resolving spontaneously, without symptoms or adverse events. Similar changes were observed on the following day and 84 days after resection, but not under the recorded conditions of weaker auxiliary water-channel flushing or manual instrument-channel spraying. When a localized whitish change is observed after strong auxiliary water-channel flushing, brief observation for spontaneous resolution may help distinguish this transient finding from a fixed mucosal lesion. Trial Registration: N/A.