Global 
Deutschland Colon to Rectum
Clin Gastroenterol Hepatol. 2026;24(1):241-249.e3
Performance of a smartphone-based stool test for use in colorectal cancer screening: Population-based study
Background and aims: Noninvasive colorectal cancer (CRC) screening bears high potential for increasing participation if implemented in a straightforward way. The authors have evaluated the feasibility and diagnostic performance of a smartphone-based fecal immunochemical test (FIT) for CRC screening and compared its performance with a laboratory-based FIT.
Methods: Individuals scheduled for a screening colonoscopy in gastroenterology practices in Southern Germany enrolled into the BLITZ study between 2021 and 2023 were offered a smartphone-based FIT and a laboratory FIT. The smartphone-based FIT consists of a rapid test and a smartphone app. The app quantitatively evaluates the result of the rapid test using the smartphone camera. The feasibility of the smartphone-based FIT was evaluated in a self-administered questionnaire. The comparative performance of the 2 FITs was evaluated by sensitivity, specificity, and receiver−operator curve (ROC) measures.
Results: Of 654 study participants who were offered both a smartphone-based FIT in addition to the laboratory FIT, 361 (55%) made use of the smartphone-based FIT, 274 (76%) of those had a valid smartphone-based FIT, and 643 (98%) used the laboratory FIT. Overall, 89% considered the smartphone-based FIT as a useful alternative offer to the laboratory FIT. The reasons why the smartphone-based FIT was not used were mostly technical (app- or smartphone-related, 47%) or reflecting more general concerns or attitudes towards such a test (44%). The smartphone-based FIT showed a sensitivity for advanced neoplasms (28%; 95% confidence interval [CI]: 13−47%) similar to the laboratory FIT (34%; 95% CI: 18−54%) at an identical specificity (92%; 95% CI: 87−95%).
Conclusions: The smartphone-based FIT could serve as an alternative in addition to currently offered laboratory FITs.