Manju Dharra, a 25-year-old Indian woman, hasn’t had a bite to eat since she was born. For the past two-and-a-half decades she has been surviving on a liquid diet consisting of milk, tea, buttermilk and water. She suffers from a rare condition called achalasia – a failure of smooth muscle fibers to relax. Because of this, the cardiac sphincter muscle does not open at all. So food cannot pass into the stomach and the gullet is blocked. The result – violent vomiting if she ever tries to eat anything solid.