 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (December 2011) |
| Melena | |
|---|---|
| Other names | Melaena, melæna |
 | |
| Pronunciation | |
| Specialty | General surgery, gastroenterology |
| Symptoms | Dark blood in stool |
| Causes | |
Melena is a form of blood in stool which refers to the dark black, tarry feces that are commonly associated with upper gastrointestinal bleeding.[1] The black color and characteristic strong odor are caused by hemoglobin in the blood being altered by digestive enzymes and intestinal bacteria.[2]
Iron supplements may cause a grayish-black stool that should be distinguished from melena,[3] as should black coloration caused by a number of medications, such as bismuth subsalicylate (the active ingredient in Pepto-Bismol), or by foods such as beetroot, black liquorice, or blueberries.[4]
- ^ MedlinePlus Encyclopedia: Bloody or tarry stools, retrieved 19 July 2010.
- ^ Walker, Brian; Colledge, Nicki; Ralston, Stuart; Penman, Ian, eds. (2014). Davidson's Principles and Practice of Medicine (22nd ed.). Edinburgh: Churchill Livingstone. p. 854. ISBN 978-0-7020-5103-6.
- ^ Navarra, Tova (2004). The Encyclopædia of Vitamins, Minerals, and Supplements. Infobase Publishing. ISBN 9781438121031.
Iron supplements cause a grayish-black stool that should be distinguished from the black, tarlike stool that occurs from bleeding ulcer.
- ^ Dugdale, David (2009-11-01). "Bloody or tarry stools". National Institutes of Health. Retrieved 2009-11-30.