Black stool indicates the patient may have a gastrointestinal bleed higher in the GI tract; occult blood may be present. A guaiac test can direct further testing. The patient with brown stool streaked with red likely has a rectal or anal fissure since the blood has not been affected by the digestive secretions. Clay-colored stool indicates an issue with getting bile into the intestines. Frothy, foul-smelling stools indicate an absorption issue in the digestive tract.