Background: The guaiac fecal occult blood test (FOBT) for colorectal cancer(CRC) screening is user dependent and not specific for human hemoglobin (Hb). The automated-developed,quantitative, immunochemical human Hb FOBT (I-FOBT) is specific, allows for quality control and selectionof a suitable Hb level, with optimal sensitivity and specificity, for colonoscopy. Material/Methods:We evaluated a desktop instrument, OC-MICROtrade mark (Eiken, Japan), which automatically develops andquantifies 50 fecal tests/hr for Hb; for ease of use, test reproducibility and stability and intra-patientdaily I-FOBT variation; clinical evaluation included sensitivity and specificity for neoplasia in patientsundergoing colonoscopy. Results: Five hundred patients prepared 3 fecal tests which were quantified forHb, I-FOBT samples were: (1) repeatedly re-examined; (2) stored at 4 degrees C or 20 degrees C or 28degrees C and re-examined; (3) I-FOBT levels correlated with colonoscopic findings. Five I-FOBTs re-examined6 times had no significant changes; 30 tests stored >/=21 days had a decay/day of: 0.3%+/-0.4 at 4 degreesC (NS), 2.2%+/-1.7 at 20 degrees C (NS) and 3.7%+/-1.8 at 28 degrees C (P

Keywords: Automatic Data Processing - instrumentation, Colonoscopy, Colorectal Neoplasms - diagnosis, Immunochemistry - instrumentation, Occult Blood, Reproducibility of Results, Sensitivity and Specificity