Dr. Trisha Pasricha is a gastroenterologist at Harvard Medical School, director of the Institute for Gut Brain Research at Beth Israel Deaconess Medical Center, and the Ask a Doctor columnist at the Washington Post. Her new book is ”You've Been Pooping All Wrong: How to Make Your Bowel Movements a Joy.”

We talk about why 95% of Americans aren't getting enough fiber, how your smartphone is giving you hemorrhoids, the surprising circadian rhythm of your colon, what the Bristol stool scale says about your health, how your gut microbiome shapes your mood and motivation, the enteric nervous system (the original brain), how early childhood trauma can rewire pain pathways for life, the gut origins of Parkinson's disease, and why you should just use the gas station bathroom.