What is achalasia, rare swallowing disorder, due to which UK woman can eat only while standing up?

Elise Baynard, a 25-year-old woman is diagnosed with a rare oesophagus disorder known as achalasia that makes it 'nearly impossible' for her to consume food and liquids normally, resulting in her being sick up to 60 times a day. She has to stand everytime she eats or drinks, as sitting would risk her choking her to death. What is her condition all about?

What is achalasia, rare swallowing disorder, due to which UK woman can eat only while standing up?
Elise Baynard, a 25-year-old woman is diagnosed with a rare oesophagus disorder known as achalasia that makes it 'nearly impossible' for her to consume food and liquids normally, resulting in her being sick up to 60 times a day. She has to stand everytime she eats or drinks, as sitting would risk her choking her to death. What is her condition all about?