I have been eating canned tuna or salmon off and on for some time and occasionally it doesn't seem to want to go down. Like it gets stuck near the bottom of my esophagus. Feels like it could come back up at times, so I stop eating it till the sensation goes away and then finish it. This may not happen everytime but seldom. Does anyone know why this happens? I don't have any other problems with other foods as far as I know. Is it the fish or the way it's prepared? Chemicals? Just wondering. Thanks. MV