Colorectal cancer is a common disease, and more reliable screening methods are needed for early detection. We aim to develop a non-invasive, stool-based assay that can identify colorectal cancer by detection of minichromosome maintenance protein 2 (MCM2) expression in colonocytes retrieved from the faecal surface. We devised a cell line model to investigate methods and conditions for optimum colonocyte retrieval. In our clinical evaluation study, MCM2-positive cells were retrieved from 37 of 40 patients with symptomatic colorectal cancer, but from none of 25 healthy control individuals. These results suggest that immunocytochemical analysis of retrieved colonocytes might enable accurate detection of colorectal cancer in stool.