The Story Behind the Stoolio Stool Scan

Stoolio is a stool scan anyone can download: point your iPhone at the bowl, and one photo returns a Stoolio Score out of 100, your Bristol type, and 12 visual readings, all tracked privately over time. It reached the App Store on May 12, 2026, it is free to try, and it needs no kit, no lab, no clinic, and no membership. This is the story behind it: why a signal the body produces every single day went unread for so long, why we believed a phone camera could change that, and what we have learned since.

A signal most people never read

Your body files a report every day. It arrives in private, requires no device and no appointment, and reflects the last one to three days of what you ate, how much you drank, how you slept, and how fast things moved. Almost nobody reads it.

Not because people don’t care — gut health is one of the most common everyday health concerns, and one of the least discussed — but because reading it has always meant one of three unappealing things: a form to fill in, a chart to interpret from memory, or a conversation nobody wants to start. So the report gets flushed, and the pattern it belonged to never forms.

Stoolio exists to close that gap. Our mission, stated plainly, is to bring awareness to gut health — to make it easier to understand, less awkward to talk about, and simpler to track over time. Everything about the product follows from that sentence.

The chart on the wall

The tool the world already uses for this is the Bristol stool scale: seven types, from separate hard lumps to entirely liquid, published in 1997 as a practical stand-in for how quickly stool moves through the gut. It hangs in plenty of gastroenterology offices, and it is genuinely useful. We built Stoolio around it rather than against it.

The weak link was never the chart. It was the reporter. When researchers tested how accurately people classify their own stool, overall accuracy came in around 81% — respectable, except that the misses clustered at the borderline types where the distinction matters most. The chart also asks one digit to stand in for several separate things: one piece or many, large or small, cracked or smooth, what color, how easy to pass. And it asks for that digit from memory, later, often in an exam room. The American College of Gastroenterology’s guidance for characterizing bowel habit is a daily diary kept for two weeks. Few people keep that diary for long. We thought the diary should keep itself.

Cameras could already read it. Most people couldn’t get one.

By the time we started, the science on scanning was already in. In a 2022 study in the American Journal of Gastroenterology, people photographed every stool for two weeks and the photos were read by software, by two expert gastroenterologists, and by the participants themselves. The software agreed with the experts at good-to-excellent levels across consistency, fragmentation, and volume; the participants’ own reports agreed with the software only moderately — and where they disagreed, the software’s readings lined up better with symptoms. A photo, it turns out, is a more reliable witness than a memory.

Yet that kind of stool scan mostly lived where it was invented: inside research studies and clinician-led programs, reached through a trial, a referral, or a benefits package. It was built to feed a care team. That is valuable work, and it is not what we set out to do. We believed the person who produces the signal should be the first person to read it — on their own phone, on their own terms, without anyone’s permission. So we built a stool scan for everyone: a consumer app you can download in a minute and try for free.

What we built

The flow is deliberately short. Point, scan, done — no forms, no sliders, no chart to squint at. A few seconds later the result opens with one number, because a number you can follow over time beats a dozen readings you have to re-interpret every visit:

• The Stoolio Score. One number, 0 to 100, labeled “based on this scan.” It is the fastest read on whether today looked like your normal, and since August 2026 every score explains itself, listing the specific findings that lifted or lowered it. (How the Stoolio Score works goes deeper.)
• Key indicators. Hydration and fiber, the two signals people act on most, open each result as a matched pair out of 100 with plain-language chips. A fat absorption indicator and an estimated transit time — shown as a range, never a false-precision single number — sit alongside.
• Stool details. Your Bristol type on the seven-type scale with a one-line description, and a color assessment placed on six named points from pale to very dark. Size and volume, fragmentation, undigested food, and mucus detection round out the 12 visual readings.
• The record. Trends across days, weeks and months; notes on any scan, including past ones; streaks that build the record for you; and a doctor-ready PDF or CSV export of any period, so an appointment starts with dated observations instead of estimates.
• A bathroom timer. A small thing with a real reason behind it: extended sessions increase pressure and strain, and a simple timer keeps them in a healthier range.

The timeline so far is short and public. Version 1.0 shipped on May 12, 2026. In August we redesigned the scan results around the two indicators people act on most and made the score show its work — without changing a single scoring rule. In September, notes started saving to any scan, past or present, so a week of scans and a week of meals can finally be read side by side.

What we don’t claim

This part matters to us, so it gets its own section. Stoolio is a consumer wellness app, not a medical device or a diagnostic tool. It does not diagnose, treat, or prevent any disease. It has not been through clinical trials, and we will never say it has. What it does is narrower and, we think, more honest: it applies the same criteria to the same visible features every single time, which is exactly what human memory can’t do, and it keeps the dated record that clinicians have been asking people to keep for decades.

A scan reads what a camera can see. Hidden blood, inflammation markers, infections, and enzyme levels are invisible by definition and belong to lab stool analysis ordered through a clinician; no photo replaces them, ours included. And a change that persists belongs in a conversation with a healthcare professional — a conversation that goes better when you arrive with weeks of readings rather than a guess. The evidence we cite on this page is independent research on the method, not a study of our app, and we label it that way on purpose.

Why it stays private

Scan data is about as personal as data gets, so the privacy stance was decided before the first line of code. Your scans exist to generate your insights — nothing more. They are encrypted in transit and at rest, they are never sold, and they are never shown to other users. Delete your account and your scan images are deleted within 90 days. There is no social feed, and nothing the camera saw is used to sell ads or target you. The full picture, in plain language, is in how Stoolio handles your data.

Why part of every subscription goes to colorectal cancer research

A stool scan is not a cancer screening test, and we say so wherever the topic comes up: screening is a clinical decision, made with a clinician, using tests built for it. But the habit Stoolio builds — noticing, and keeping a record — is the same habit that gets people to those conversations sooner. That is why a portion of every Stoolio Pro subscription supports colorectal cancer research. It is a small way of pointing the product at the outcome that matters most.

Where this goes

A stool scan gets more useful the longer it runs. One reading is trivia; a few weeks of readings is a baseline, and a baseline is what makes a real change visible. So most of what we build next serves the record: making it easier to keep, easier to read, and easier to bring into a conversation that counts.

We are a small team in Fort Lauderdale, and the roadmap is shaped by the people using the app. More than 41,000 people follow @stoolioscan, and the conversation there is a daily reminder that this subject is far less awkward than everyone assumes once someone goes first. If there is something you wish the scan did, tell us. The score breakdown exists because people kept asking why their number landed where it did.

Try the stool scan today

Unlike a scan delivered through a care program, this one takes about a minute to get. Download Stoolio on the App Store, take a scan, and your first three are free — a complete readout, score and all, before you decide anything. Ongoing scanning is part of Stoolio Pro at $29.99 a year or $9.99 a month, with 35 scans per 30 days, which is enough to scan every day. If you would rather start by hand, our free Poop Check walks consistency and color without a download, and what a stool scan is explains the method from the ground up.