Occult blood

Overview
Occult blood is blood in the feces in amounts that cannot be seen by the eye however it can be detected through tests.

Differential diagnosis of causes of occult blood
In alphabetical order.

Causes
 * Angiodysplasia of the colon
 * Arteriovenous malformation
 * Diverticula
 * Esophageal varices
 * Fissures
 * Gastrointestinal trauma
 * Gastrointestinal tumor
 * Gastric carcinoma
 * GM-CSF Therapy
 * Hemorrhoids
 * Hiatal hernia
 * Infections
 * Inflammation
 * Intestinal polyposis
 * Loeffler's syndrome
 * NSAIDs
 * Portal hypertension