Acquiring Bowel Movement Data Just by "Sitting"—The Healthcare Revolution of "Toilet Scanning" Pioneered by TOTO's New 'Neorest LS-W/AS-W'

1. Background—Next-Generation Data Sought by the "Gut Health" Market

With the Japanese government's goal to extend healthy life expectancy by three years (2025~2035) and advancements in gut flora research, the yogurt, probiotics, and personal supplements market has been growing at a rate of 12% year-on-year. However, objective data on bowel movements faces challenges such as being "troublesome" and "difficult to consistently record," and there were virtually no products that could convert quantitative information into life logs.

In an internal survey by TOTO, **76%** of respondents said they "visually check their stool," but only 6% of them record it in an app. TOTO Ltd.

As a solution to bridge this gap, the leading toilet manufacturer chose "unconscious" data collection.

2. Product Overview—NEOREST LS-W/AS-W

2-1. Sensor Structure

• Near-Infrared LED + Photodetector for high-speed scanning of stool surface

• Machine Learning Algorithm estimates Bristol Scale 7 stages, color information, and volume within 0.1 seconds

• Measurement Error: Hardness ±0.3 stages, Color ΔE*ab±3, Volume ±5 mL (TOTO internal verification values)
  
  

2-2. App "TOTO Wellness"

• Charting of stool conditions for the past 30 days

• Integrates diet, sleep, and exercise logs to calculate "Gut Age" score

• Easy sharing with medical institutions via CSV export function

3. Technical Details—Training Data for Stool Scanning AI

In collaboration with seven medical institutions, TOTO collected over 32,000 anonymized stool images. After color correction, hardness tags were assigned, and learning was conducted using a Res-Net derived CNN. The Lab color space was adopted for color estimation, and differences in lighting conditions were corrected using a proprietary algorithm. Volume estimation applied point cloud analysis (Poisson Surface Reconstruction) with depth sensors, maintaining an average error of 5 cm³.

4. Consumer Benefits—Visualization Promotes Behavioral Change

• Reduced Constipation Risk: Displays warnings when hardness score is 5 or above and sends hydration reminders

• Early Disease Detection: Detects black or tarry stools and alerts to the possibility of gastrointestinal bleeding

• Family Management: Supports personal settings for up to four users, maintaining privacy while monitoring family gut health
  
  

In a verification experiment by Nagoya City University (n=120), the group with stool scanning achieved an 18% increase in dietary fiber intake, an 11% increase in fluid intake, and an average increase of 1.8 bowel movements per week over four weeks.

5. Market Impact and Challenges

5-1. Global Competition

The "precision-health toilet" prototype announced by Stanford University in 2020 and the stool sensors by Israel's OutSense are primarily for clinical use and are expensive, but TOTO's differentiation point is its appeal to general households by keeping the price in the 500,000 yen range. Stanford MedicineThe Guardian

5-2. Privacy Protection

Stool data is often referred to as "the ultimate personal information." TOTO adopts a design that immediately discards image data through edge processing and encrypts only numerical data for cloud transmission. They plan to obtain dual certification with the international standard ISO/IEC 27701 and Japan's Privacy Mark.

6. Future Outlook—"Water-Related Health Tech" Ecosystem

• Bathroom Integration: Analyzes dehydration risk with shower water volume and heart rate measurement

• Washbasin Camera: AI determines complexion and eye redness for correlation analysis with gut condition

• Medical DX: Real-time integration with online medical platforms via TOTO Wellness API
  
  

By 2027, TOTO aims to obtain FDA and CE certifications with a view to entering the North American and European markets, and the global smart toilet market size is expected to reach $24.5 billion by 2030.

7. Conclusion

The "NEOREST LS-W/AS-W" transforms the everyday space of the toilet into a "sensing hub," bringing the hurdle of obtaining gut environment data close to zero. As stool scanning becomes widespread, the vague concept of "good bowel movements = health" will be quantified, accelerating the prevention and early treatment of lifestyle diseases.

TOTO's challenge holds the potential to extend beyond the domestic health tech industry and contribute to the improvement of global public health.

🔗 List of Reference Articles (Click to External Sites)

1.  Scanning Quantity, Shape, and Color for Health Management: TOTO to Release Latest Toilet｜Mainichi Newspaper

2.  What is TOTO's "Stool Scanning" Toilet? Managing Health with Bowel Movement Data｜Kaden Watch

3.  TOTO News Release: "NEOREST LS-W/AS-W" to be Released on August 1, 2025

4.  Smart Toilet Monitors for Early Signs of Disease｜Stanford Medicine

5.  The Smart Toilet Era Is Here｜The Guardian