C-sections are the most frequently performed major surgeries in the world. So why do so many patients feel severe pain during them? Season 2 of the award-winning podcast “The Retrievals” is an investigation into this underreported problem — and the new effort to solve it. To get full access to this show, and to other Serial Productions and New York Times podcasts on Apple Podcasts and Spotify, subscribe at nytimes.com/podcasts.   To find out about new shows from Serial Productions, and get a look behind the scenes, sign up for our newsletter at nytimes.com/serialnewsletter.    Have a story pitch, a tip, or feedback on our shows? Email us at serialshows@nytimes.com