Every 3 months for a lot of years. They put you in la la land and while they put the scope down your esophagus, they take small biopsies. After and most of the time you don't even notice it after uless the biopsy is one a little larger. Mine is from Esophageal surgery in 1996.

Since posting this. UPMC, Pittsburgh, Oct 2011 until Jan. I averaged about 2 to 3 surgeries a week there. w Can't have jaw made as bone is deteroriating steaily that is left in jaw. Mersa is to blame. Feeding tube . Had trach for 4mos. Got it out April.
--- Passed away 5/14/14, will be greatly missed by everyone here