Other colon cancer screening tools such as iFOBT (immunochemical fecal occult blood test) or colonoscopy are also included in guidelines.

[5] In 2009, the American College of Gastroenterology (ACG) suggested that colon cancer screening modalities that are also directly preventive by removing precursor lesions should be given precedence, and prefer a colonoscopy every ten years in average-risk individuals, beginning at age 50.

[8] The United States Preventive Services Task Force (USPSTF)'s 2016 recommendation, instead of emphasizing specific screening approaches, has instead chosen to highlight that there is convincing evidence that colorectal cancer screening substantially reduces deaths from the disease among adults aged 50 to 75 years and that not enough adults are using this effective preventive intervention.

MSTF looked at six studies that compared high-sensitivity gFOBT (Hemoccult SENSA) to FIT, and concluded that there was no clear difference in overall performance between these methods.

[11][12] However, research carried out in the UK has suggested that the FIT threshold for further investigation is set at a point that may miss more than half of bowel cancer cases and only identifies one in four high-risk polyps.

[16][17][18][19] If colon cancer is suspected in an individual (such as in someone with an unexplained anemia), fecal occult blood tests may not be clinically helpful.

[21] In colon cancer screening, using only one sample of feces collected by a doctor performing a digital rectal examination is discouraged.

[29] However, chemical confirmation that coloration is due to blood rather than coffee, beets, medications, or food additives can be of significant clinical assistance.

[31] Approximately one third of endurance runners experience transient but exercise-limiting symptoms, and repetitive gastrointestinal bleeding occasionally causes iron deficiency and anaemia.

[35] Substantial changes occur in stress hormones including cortisol, in circulating concentrations and metabolic behavior of various leucocytes, and in immunoglobulin levels and major histocompatibility complex expression.

[36] Symptoms can be exacerbated by dehydration or by pre-exercise ingestion of certain foods and hypertonic liquids, and lessened by adequate training.

These look at different properties, such as antibodies, heme, globin, or porphyrins in blood, or at DNA from cellular material such as from lesions of the intestinal mucosa.

Additional methods of looking for occult blood are being explored, including transferrin dipstick[48] and stool cytology.

[56] Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding.

[61] Safety regulations from US accreditor the Joint Commission may have unintentionally decreased digital rectal examination and FOBT in hospital settings such as Emergency Departments.