Welcome to Healing Well! While I have not experienced this procedure, I'm sure there are others here who have. I expect they will respond to your post soon, and share their experiences. I know I have read other posts regarding this procedure.
Here is a website from Johns Hopkins University that provides some information. You may have seen it, but just in case you haven't, check it out:apps.pathology.jhu.edu/blogs/barretts/?p=27
I wish your husband the best of luck with treating his Barrett's. I expect others will be by soon to respond to your post!