Social media provides a useful platform for informal discussions about healthcare. Acceptability is key to the uptake of diagnostic devices and this can be difficult to gauge from questionnaires and qualitative studies. The aim of this study is to investigate whether Facebook could be used to gauge public perception toward uptake of a new diagnostic test for Barrett's esophagus called the Cytosponge. We retrospectively reviewed Facebook comments relating to a video on the Cytosponge. We categorized comments into: (1) Positive, (2) Negative, (3) Unknown and (4) Questions. Recurring themes that arose were compared to a qualitative study on the Cytosponge. The video received 22.5 million views and 2837 comments within four months. Of these, 525 comments were positive, 215 were unknown, 179 were negative, 71 were questions, and 1847 were 'Tagged' comments. Among positive comments, recurrent themes were that it was innovative, could lead to early cancer-detection, and more favorable than endoscopy. Among negative comments, a recurring theme was concern about the risk of gagging and vomiting. Among 'questions', a recurring theme was related to the risk of Cytosponge detachment. We compared our analysis to a published qualitative study and found similar themes arose across both studies. Facebook provides a rich source of qualitative data, which could be used to augment studies to gauge public perception toward a new diagnostic test.