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How to poop better, according to a gastroenterologist

April 1, 2026·29 min·2 clips

Using your phone on the toilet raises your hemorrhoid risk by 46%, according to a Harvard gastroenterologist's study.

1. Science Friday's Flora Lichtman interviews Dr. Trisha Pasricha, a Harvard neurogastroenterologist and author of 'You've Been Pooping All Wrong,' on the mechanics, health signals, and stigma of bowel movements. 2. Dr. Pasricha is a second-generation gastroenterologist — her father, also a neurogastroenterologist, asked about bowel movements at the dinner table instead of homework, normalizing the topic for her from childhood. 3. The episode's central argument is that collective poop shame is a genuine public health problem: one in three people with GI symptoms avoid discussing them with their doctor out of embarrassment. 4. Dr. Pasricha's lab conducted a study showing that people who use smartphones in the bathroom are at a 46% increased risk of developing hemorrhoids — not because they strain more, but because they are more than five times as likely to spend over five minutes sitting passively on an unsupported pelvic floor. 5. The mechanics behind squatting: the puborectalis muscle creates a sling that 'kinks the hose' of the colon when sitting at 90 degrees; squatting or raising knees above waist level straightens that kink and reduces straining. 6. Stool color is explained: brown comes from bilirubin, a digestive juice stored in the gallbladder — without it, stool would be pale white; white or clay-colored stool means bile is blocked and is a medical emergency (possible gallstone or cancer), except in the specific case of barium contrast from a medical procedure. 7. Bright red blood, maroon stool (unless beet consumption accounts for it), and black tarry stool are also emergency signals for gastroenterologists — the Portlandia '911 beet salad' sketch is cited as a known reference in GI medicine. 8. The TRPV1 receptor, subject of the 2021 Nobel Prize in medicine, explains why spicy food burns both on entry and exit: capsaicin signals the same pain receptor as heat throughout the gastrointestinal tract, speeding colonic contractions. 9. The 'fart walk' — a short brisk walk of five to ten minutes after eating — is backed by gastroenterology research to move intestinal gas more efficiently; simply sitting upright instead of lying down moves gas 33% more efficiently. 10. Ninety percent of vagus nerve signaling runs from the gut upward to the brain, not the other direction — a finding from the 1990s that upended the field of neurogastroenterology. 11. Depression and anxiety can originate in the gut rather than the brain, according to current neurogastroenterology research. 12. Dr. Pasricha holds an NIH grant to study Parkinson's disease — unusual for a gastroenterologist — based on evidence that the disease may begin in the gut. 13. Eighty percent of Parkinson's patients have GI issues, and those issues — particularly new-onset constipation in middle age — can appear years or even decades before tremors or a neurological diagnosis. 14. The alpha-synuclein protein, which misfolds in Parkinson's disease and kills dopamine neurons, is found in the guts of Parkinson's patients; the hypothesis is that a trigger (infection, diet, or stomach ulcer) causes misfolding that travels up the vagus nerve to the brain over years. 15. The clinical promise of this model is that a colonoscopy could one day detect alpha-synuclein misfolding early enough to intervene before neurological damage occurs. 16. Colorectal cancer recently became the leading cause of cancer-related deaths in adults under 50, leading Dr. Pasricha to change her clinical practice — she now considers cancer in younger patients presenting with rectal bleeding. 17. Only about a quarter of people aged 45 to 50 who are eligible for covered colonoscopy screening are actually getting it; insurance covers colonoscopies under 45 only for symptomatic patients or those with a relevant family history. 18. Ultra-processed foods and sugar-sweetened beverages consumed in adolescence are linked in recent studies to rising rates of early-onset colorectal cancer, partly through fiber displacement and gut lining disruption. 19. The episode is conversational and lightly humorous — puns are flagged throughout, listener voicemails include a roundworm sighting and a white-poop mystery — but the clinical information is consistently specific and grounded in named studies. 20. Best for listeners interested in gut health, preventive medicine, or early-warning signals for serious diseases; less suited to those who find the subject matter uncomfortable despite the host's content warning framing it as 'delightful.'

As heard by us

A frank, funny Science Friday segment turns poop shame into practical gastroenterology, from stool-color warnings to spicy-food biology.

Science Friday turns bathroom embarrassment into a real health conversation, with Dr. Trisha Pasricha arguing that poop shame can keep people from noticing what their bodies are trying to say.

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Everything your gut has been trying to tell you, explained by a Harvard gastroenterologist.

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