I will tell you what I have found at least for me. When this occurs it usually occurs to me when I am very thirsty and upon the first few drinks. I believe it is from being too dry. and once you have lubricated the throat again the pain subsides and it is easier but sometimes it takes a few drinks and I find that if I take small sips at first to lubricate it hurts less and then I can drink normally!
That has happened several times lately as my water intake has been dereased.. That really hurts when that happens..