Stool Testing and Interpretation

A stool specimen can answer very different clinical questions: whether an asymptomatic person is due for colorectal cancer screening, whether diarrhoea is caused by an enteric pathogen, whether intestinal inflammation is present, or whether pancreatic enzyme delivery is inadequate. The result is only as useful as the match between the test, the specimen, and the patient’s presentation. Canadian colorectal cancer screening is organized through provincial and territorial programs rather than one national protocol. The 2016 Canadian Task Force on Preventive Health Care guideline recommends FIT or FOBT every 2 years for average-risk adults aged 50 to 74, while provincial programs increasingly use FIT at one- to two-year intervals and may use different start ages. Ontario’s ColonCancerCheck program lowers average-risk eligibility to ages 45 to 74 effective July 1, 2026. Apply the program and laboratory pathway used in the patient’s province; a US recommendation for annual FIT beginning at age 45 is not automatically the Canadian answer. Occult blood testing is a screening tool for asymptomatic average-risk adults, not a diagnostic rule-out test. Overt rectal bleeding, iron-deficiency anaemia, unexplained weight loss,...