Smart Toilets Are Booming — But the Science Hasn't Caught Up Yet

A quiet revolution is underway in bathroom technology, moving well beyond heated seats and bidets into genuine health surveillance. In the past 18 months alone, three major players have entered the market: Japanese plumbing giant TOTO launched Stool Scan using LED-based analysis in Japan (with a US debut planned for early 2027); wellness startup Vivoo released a Smart Toilet focused on urine and hydration metrics; and Throne Science — cofounded by WHOOP cofounder John Capodilupo, who has ulcerative colitis — shipped its clip-on camera device to customers and closed a $10 million Series A. Kohler and Withings have also launched competing products. Brian Comiskey of the Consumer Technology Association says the category genuinely took off in 2023, driven by better optical sensors, AI, and growing consumer anxiety about gut health, but 2025-2026 is when it's hitting its stride.

Throne's device clips onto the toilet bowl, uses a proximity sensor to identify which household member is using it, and runs stool images through AI trained with gastroenterologist input to assess consistency and urine color. The data feeds into an app with trend charts and an 'AI gut health coach' that cross-references food, stress, sleep, and travel logs to suggest correlations. Throne CEO Scott Hickle's long-term pitch is bold: he describes the product's potential as a 'smoke detector for colon cancer,' and the company is developing multispectral imaging to detect microscopic blood and exploring gas-sensing biomarkers.

Gastroenterologists are genuinely intrigued — but measured. Kyle Staller of Massachusetts General Hospital and Harvard Medical School acknowledges the appeal of objective stool diaries, since patients are notoriously unreliable at self-reporting bowel habits. Brennan Spiegel of Cedars-Sinai says he would use patient-submitted diary data, especially when adjusting medications or evaluating treatment response. But both doctors flag a hard scientific ceiling: the devices can document what happened in the toilet; they cannot reliably explain why. Stress, hormones, genetics, travel, medications, infections, and diet all influence digestion, and microbiome science hasn't yet produced validated, personalized recommendations.

The deeper diagnostic problem is even thornier. If a smart toilet detects blood, it cannot distinguish between hemorrhoids, menstruation, inflammatory bowel disease, or colorectal cancer — conditions requiring very different responses. Spiegel is blunt: no validated literature currently supports these technologies making that distinction. Staller adds a psychological concern: for people without existing bowel issues, constant data streams risk turning normal variation into a source of anxiety and obsession. For now, every device on the market is classified as a wellness product, not a medical one — diagnosing conditions would require FDA clearance.

Still, the trajectory is clear. Comiskey draws a direct parallel to wearables, where atrial fibrillation detection migrated from consumer gadget to regulated medical feature. He predicts mass adoption within six to ten years, with new homes already being built with integrated smart toilets and clip-on devices shrinking and becoming cheaper. The toilet's key advantage over wearables is unavoidable: you will always use it. TOTO frames this as an 'immediate and ongoing interface' — no charging, no forgetting to strap it on. Spiegel envisions a future of 'blended intelligence,' where AI-flagged signals are filtered through human clinical judgment, eventually turning the bathroom into a routine diagnostic checkpoint.