Abstract: A method for detecting neoplasia or cancer of the colon or rectum comprising obtaining a sample of colorectal mucus from the rectum of a patient, and detecting the presence of a marker selected from the group consisting of long chain aliphatic aldehydes containing 12-20 carbon atoms, particularly CH3(CH2)14CHO and CH3(CH2)16CHO; and plasmalogen-bound precursors thereof. Preferably the method comprises treating the sample with Schiff's Reagent and detecting neoplasia or cancer of the colon or rectum based upon the coloration produced at about 560-590 nm in the sample by the treatment. The method does not require the step of adding an enzyme for detecting the disaccharide marker &bgr;-D-Gal(1-3)-D-GalNAc(&agr;1-Thr/Ser) and a saccharide marker containing D-galactose and/or 2-acetamido-2-deoxy-D-galactose.

Abstract: A method for detecting the presence of neoplasia or cancer of the colon or rectum, which method comprises obtaining a sample of colorectal mucus from the rectum of a patient; treating the sample with Schiff's reagent and screening for neoplasia or cancer of the colon or rectum based upon the coloration produced in the sample by the treatment. The method is rapid, simple, inexpensive and provides a screening test for colorectal cancer which does not give a high percentage of false positive and false negative results. A screening test kit is provided.