A fecal occult blood test is a test used in a stool sample to detect occult or not grossly visible blood (usually requested for patients with complaints of blood streaked stools or black and tarry stools). This patient also exhibits a significant weight loss (4.5 kg in the span of one month). Given these signs and symptoms, the patient may have a probable colonic malignancy and a referral to a doctor should be made by the nurse. Before doing the fecal occult blood test, the patient should be asked to restrict citrus fruits and vitamin C as they may confound with the results.