Melena is a form of digestive hemorrhage. This is, in most cases, hemorrhage (blood loss) from the right angle of the colon.
Definition of melena
Melena is a form of hemorrhage of the digestive system. It is then the evacuation of black blood, through the anus.
This type of gastrointestinal bleeding results in an expulsion of blood from the digestive system: digestive tract, bile ducts or even from the pancreas.
Melena, however, is not to be confused with other digestive haemorrhages and other intestinal complications: blood sputum, nasal bleeding, gynecological bleeding such as menstruation, etc.
In addition, high haemorrhages (whose origin is upstream of the duodenojejunal angle) are to be differentiated from low haemorrhages (whose origin is downstream of this angle). Melena is then a low hemorrhage. and in most cases comes from a haemorrhage of the right angle of the colon.
The causes of melena
Different causes can be at the origin of a melena:
- the presence of a polyp (outgrowth of intestinal mucosa) or cancer
- diverticular bleeding (caused by small hernias formed in the intestinal wall)
- ischemic colitis, infectious, inflammatory or radiation
- a rectal ulcer (especially in the elderly)
- Hemorrhoidal bleeding from hemorrhoids
In rare cases, melena can originate from angiodysplasia, tumors, and nonsteroidal anti-inflammatory drug (NSAID) ulcerations.
Who is affected by melena?
People suffering from disorders in the digestive system are at greater risk of melena (gastric or intestinal ulcer, ischemic colitis, etc.).
Older people are also at greater risk of melena.
The symptoms of melena
The clinical signs of melena result in:
- the emission of black blood, accompanied by a foul odor, in the stool
- intestinal pain
Risk factors of melena
The main risk factors for melena correspond to the different possible causes. Either the presence of haemorrhages in the intestinal system, the presence of ulcers, colitis, etc.
How to treat melena?
The diagnosis of the disease is confirmed or reversed following an endoscopy.
The management of the treatment of low hemorrhages depends on the origin of these. It can be a simple therapeutic treatment, an endoscopic ablation or a particular diet to follow.