AbstractBackgroundThe fecal occult blood (FOB) test is one of the primary screening methods for colorectal cancer (CRC). In this study, we aimed to investigate the effect of the neutrophil/lymphocyte ratio (NLR) and systemic immune‐inflammation index (SII) in predicting CRC and other colorectal pathologies in patients with a positive FOB test.MethodsThis retrospective study included patients with a positive FOB test who underwent colonoscopy for the investigation of the etiology. The optimal cutoff levels of NLR and SII for predicting colorectal pathologies were determined using the receiver operating characteristic analysis.ResultsOf the 157 FOB+ patients, 35% were male and 65% were female, with a median age of 59 years. There were 96 patients in Group 1 and 61 patients in Group 2. The mean age of the patients in Group 2 was significantly higher (p< 0.001). The rate of male patients was significantly higher in Group 2. NLR and SII were significantly higher in Group 2 than in Group 1 (p< 0.001). The area under the curve values of NLR and SII in predicting colorectal pathologies in FOB+ patients were 0.817 and 0.825, respectively. At the cutoff values of 0.689 and 0.795, NLR and SII had a sensitivity of 60.66% and 95.83%, respectively, and a specificity of 95.83% and 100%, respectively.ConclusionNeutrophil/lymphocyte ratio and SII can be used as important biomarkers in the early diagnosis of CRC and other colorectal lesions in patients with a positive FOB test.