Diagnosis is often based on direct observation of blood in the stool or vomit. Although fecal occult blood testing has been used in an emergency setting, this use is not recommended as the test has only been validated for colon cancer screening. Differentiating between upper and lower bleeding in some cases can be difficult. The severity of an upper GI bleed can be judged based on the Blatchford score or Rockall score. The Rockall score is the more accurate of the two. As of 2008 there is no scoring system useful for lower GI bleeds. Clinical Gastric aspiration and or lavage, where a tube is inserted into the stomach via the nose in an attempt to determine if there is blood in the stomach, if negative does not rule out an upper GI bleed but if positive is useful for ruling one in. Clots in the stool indicate a lower GI source while melana stools an upper one. Laboratory testing Recommended laboratory blood testing includes: cross-matching blood, hemoglobin, hematocrit, platelets, coagulation time, and electrolytes. If the ratio of blood urea nitrogen to creatinine is greater than 30 the source is more likely from the upper GI tract. Imaging A CT angiography is useful for determining the exact location of the bleeding within the<unk>  tract. Nuclear scintigraphy is a sensitive test for detecting occult<unk>  when direct imaging with upper and lower endoscopies are negative. Direct angiography allows for embolization of a bleeding source, but requires a bleeding rate faster than 1mL/minute.
Gastrointestinal bleeding
Internal bleeding
Lower gastrointestinal bleeding
Upper gastrointestinal bleeding
Enteropathy
Rectal bleeding
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