Colorectal cancer is common cancer and had high rate of mortality and morbidity, and this can be reduced by screening tests. A number of studies have recently referred to RDW as a marker for early detection cancers. The aim of this study was investigating the Relation between Distribution of Red Blood Cells (RDW) and Early Detection of Colorectal polyp and Colon cancers.

The sample size is 90 people divided into three groups of 30 people, one group includes people who have colon cancer, a group of people with colon polyps, and a group of people with normal colonoscopy as a control and compared RDW-HB-MCV-PLT-FERRITIN-SERUM IRON-TIBC in patients.

Based on area under the receiver operating characteristic curve (AUC) analysis, RDW (AUC = 0.002) had a predictive value for colorectal cancer with cut off >14 with 80 % sensitivity and 60% specificity along with HB, IRON, Transferrin saturation.

RDW can be considered as a parameter for predicting colorectal cancer along with HB, IRON, T sat.