Butt Talks: AI stool analysis, a gut health score, and a nurse behind it
Your poop talks. Time to listen.
The product
Butt Talks is a gut health tracker. You take a photo of your poop, the app's AI (named Butty) types it on the Bristol stool scale, 1 to 7, and writes one line on what that type means. The log saves with its date and time, so a few seconds in the bathroom builds a history you can read back.
It was built with Nurse Wong, RN BSN, co-author of The Power of Pooping, who has been featured in Parade, Smithsonian and the San Francisco Examiner. Her courses, product recommendations, 1-on-1 video calls and a Discord community live inside the app under Gut Hub.
The app is free to start, with unlimited analysis at $9.99 a month. It is on the App Store for iPhone, rated 4.3 from 12 ratings at time of writing. The website is at butttalkstv.com.
What I built
This was a rebuild. The original app had been on the App Store since 2021. The work covered the website and the iPhone app, in one monorepo with shared packages for core logic and design tokens.
The website is Next.js. The landing page is a server component with a scroll-driven animated background, a product tour, pricing, video proof, the press and book section, testimonials and an FAQ. Every section is an analytics key, so section views are tracked in PostHog, and a free guide lead magnet collects email for the nurse's list. The page has a layout and Playwright end-to-end tests that assert on rendered pixels, because an opaque body background would hide the animated layer entirely.
The iPhone app is Expo and React Native with a native StoreKit module for subscriptions, Sign in with Apple, and secure on-device storage for the session. Version 3.5 is the current release.
What the app does
A log can hold more than the photo:
- A Bristol type, from the AI or picked by hand from the seven
- Colour, pain from 0 to 10, glasses of water
- Straining, urgency, and whether it felt complete
- Sleep, a note on what you ate, medication
- Location, if you want it
Every typed log feeds one number for the last 7 days, drawn on a gauge from 10 to 96. Type 4 is the ideal, and both ends of the scale count equally against you, so a 1 and a 7 score the same. Four colour bands, green through red. The score is not a diagnosis, and the app says so.
Home shows Butty's read on your week in plain English, your most recent log, your most common type over 7, 30 or 60 days, a distribution chart, a calendar marking every logged day with its type and score, 30-day trends for type, frequency, pain, water and medication days, a map with a pin on every log saved with location, a streak count, and a card that flags a log worth a second look, such as a colour that warrants checking.
The hard parts
Photo classification on a sensitive subject. The camera screen frames the toilet bowl with a dashed guide and the photo goes to a vision model that returns a Bristol type and a short explanation. The fallback is always one tap away: pick the type yourself from a picture grid. Nobody should be stuck because the model was unsure.
Scoring that reads as fair. A score that only penalised constipation or only penalised diarrhoea would read as wrong to half the users. Treating distance from Type 4 symmetrically, and showing the bands rather than just a number, made it something people trust enough to keep logging.
A paywall that does not block logging. Logging is free. Unlimited AI analysis is the paid part. The subscription runs through StoreKit, and the free tier has to feel complete on its own or nobody reaches the second week.
Butt Talks is on the App Store for iPhone. Android is coming, and the Google Play badge on the site opens a waitlist until it ships.
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