What Causes A Sensation Of Food Stuck In Esophagus?

Occasionally when I swallow my food, it sometimes seems to be stuck in the esophagus, It is painful at times, I can bring up the food with little effort, Swallowing some water afterwards clears up this situation. This does not alway happen but when I feel food being stuck, I extend my neck into a straight position, swallow some water & the situation clears itself. Problem is that this doe not always happen & I have to literally expel the swallowed food or drink which could be very embarasing at the table to say the least, Can you offer some explanation or cause of what is happening? Thank you for your prompt reply.