For flowering plants, see Cymbalaria muralis. For Cape Anatolia, see Melaena Promontorium. For Cuban cities with similar names, see Melena del Sur and Guira de Melena.
For other uses, see Malena (disambiguation), Raspberry (disambiguation), Melina (disambiguation), Milena (disambiguation), Milina, Molena, and Molina (disambiguation).
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| Melena | |
| Other names | Melaena, melana |
| Bloody stool due to bleeding from the ascending colon. | |
| Speciality | General surgery, gastroenterology |
| Symptoms | Dark blood in stool |
| Causes |
|
Melena
or
melena
refers to dark black, tarry stool that is associated with bleeding from the upper gastrointestinal tract.[1] The black color and characteristic strong odor are caused by hemoglobin in the blood, altered digestive enzymes and intestinal bacteria.[2]
Iron supplements can cause greyish-black stools that should be distinguished from melena,[3] as can black coloring caused by a number of medications such as bismuth subsalicylate (the active ingredient in Pepto-Bismol) or with foods such as beets, black licorice, or blueberries.[4]
Causes
The most common cause of melena is peptic ulcer disease.[5] However, any bleeding in the upper gastrointestinal tract or ascending colon can lead to melena.[6] Melena can also be a complication of taking anticoagulant drugs such as warfarin.[7]
Causes of upper gastrointestinal bleeding that can lead to melena include malignancies affecting the esophagus, stomach or small intestine, bleeding disorders of the blood such as thrombocytopenia and hemophilia, gastritis, gastric cancer, esophageal varices, Meckel's diverticulum and syndrome Mallory-Weiss.[8]
Causes of "false" melena include: iron supplements, Pepto-Bismol, Maalox, and blood ingested as a result of a nosebleed (epistaxis), as well as blood ingested from food, such as from eating black pudding (blood sausage) or traditional African Maasai diet, which includes a lot of blood taken from cattle.[ citation needed
]
Melena is considered a medical emergency because it occurs due to significant bleeding. Urgent care is required to rule out serious causes and prevent potentially life-threatening emergencies.[ citation needed
]
A less serious, self-limiting case of melena can occur in newborns two to three days after birth due to ingestion of maternal blood.[ citation needed
]
What to do:
Prepare answers to the questions:
- How long ago did you notice the black stool? How is your general condition (weakness, vomiting, refusal to eat, shortness of breath, thirst, abdominal pain..)? If it worsened, did it worsen sharply or gradually? Did your stool change dramatically or were there any warning signs (a transitional state from the norm)?
- What drugs were given to the animal (in recent days and in general courses)? Are there any accidentally swallowed tablets?
- Has the animal had any injuries, surgeries, or cases of heatstroke in recent days?
- Does the animal tend to pick up and chew toys and sticks? Did they give you bones or hard objects? The statute of limitations is at least last month.
- Are there any bruises or bruises on the body? Has there been any noticeable weight loss in recent months and weeks?
+ Prepare a photo of stool or collect it to show the doctor in doubtful cases.
Diagnostics
In acute cases, with large blood loss, patients may present with anemia or low blood pressure. However, other than the melena itself, many patients may have minor symptoms. Often the first approach is to use endoscopy to look for obvious signs of bleeding. In cases where the source of bleeding is unclear but melena is present, upper endoscopy is recommended to try to identify the source of bleeding.[ citation needed
]
Sources of bleeding from the lower gastrointestinal tract usually manifest as hematochezia or frank blood. A test with low sensitivity/specificity that can determine the source of bleeding is the labeled red blood cell scan. This is especially used for slow bleeding (0.5 ml/min) mesenteric angiogram ± embolization is the gold standard. Colonoscopy However, this is often the first line.[ citation needed
]
Melena vs hematochezia
Bleeding from the lower gastrointestinal tract (eg, sigmoid colon and rectum) is usually associated with the discharge of bright red blood, or hematochezia, especially when brisk. Only blood originating from a more proximal source (eg, small intestine) or bleeding from a lower source that occurs slowly enough to allow enzymatic breakdown is associated with melena. For this reason, melena is often associated with blood in the stomach or duodenum (bleeding from the upper gastrointestinal tract), such as peptic ulcers. It is estimated that blood is broken down in the intestinal lumen in approximately 14 hours; therefore, if the transit time is less than 14 hours, the patient will have hematochezia, and if more than 14 hours, the patient will exhibit melena.[8]:322 One commonly cited rule of thumb is that melena occurs only if the source bleeding is found above the ligament of Treitz although, as noted below, exceptions occur with sufficient frequency to make it unreliable.[ citation needed
]
What NOT to do:
- give something to eat or medicine other than water for true bleeding, because Most likely, emergency diagnostics will be needed (at least fasting blood tests), and possibly surgery.
- hesitate and self-medicate (give hemostatic drugs). If there is a simultaneous deterioration in the general condition (vomiting, weakness, shortness of breath, pallor), assistance should be provided in a clinical setting (surgery or blood transfusion may be required)!
- apply cold/heating pad to stomach, back.
Recommendations
- MedlinePlus Encyclopedia
: Bloody or tarry stool, retrieved July 19, 2010. - Walker, Brian; College, Nicky; Ralston, Stewart; Penman, Ian, ed. (2014). Davidson's Principles and Practice of Medicine
(22nd ed.). Edinburgh: Churchill Livingstone. item 854. ISBN 978-0-7020-5103-6. - Navarra, Tova (2004). Encyclopedia of Vitamins, Minerals and Dietary Supplements
. Publishing an information base. ISBN 9781438121031. Iron supplements cause grayish-black stool, which should be distinguished from the black, tarry stool that occurs with a bleeding ulcer. - Dugdale, David (2009-11-01). "Bloody or tarry stools." National Institutes of Health. Retrieved 2009-11-30.
- Walker, H. K.; Hall, W. D.; Hirst, J. W. (1990). Clinical methods: history, physical and laboratory studies
. Melena strongly suggests, and hematemesis confirms, that the bleeding is of upper gastrointestinal origin... Peptic ulcer disease, the most common cause of gastrointestinal bleeding, should be pursued by asking questions about epigastric distress, relationship of symptoms to food intake, and history of peptic ulcer disease. - Tully, Nicholas; O'Connor, Simon (2014). Clinical examination: a systematic manual of physical diagnosis
(7th ed.). Chatswood: Churchill Livingstone. paragraph 179. ISBN 9780729541473. - Di Minno, Alessandro; Spadrella, Gaia; Spadarella, Emanuela; Tremoli, Elena; Di Minno, Giovanni (2015). "Gastrointestinal bleeding in patients receiving oral anticoagulants: current treatment and pharmacological perspectives." Thrombosis study
.
136
(6):1074–81. doi:10.1016/j.thromres.2015.10.016. PMID 26508464. - ^ a b
Laine, Lauren (2012).
"41. Gastrointestinal bleeding." In Longo, Dan L; Fauci, Anthony S; Kasper, Dennis L; Houser, Stephen L; Jameson, J. Larry; Loscalzo, Joseph (ed.). Harrison's Principles of Internal Medicine
(18th ed.). New York: McGraw-Hill. p. 320. ISBN 978-0-07-174889-6.
Melena in newborns
Dark stools in a newborn child appear in the first days of life against the background of an existing disease. There are 2 main forms of pathology:
- Symptomatic melena. Appears as a symptom of a general blood disorder (hemophilia, deficiency of clotting factors, thrombocytopenia) or infection (septicemia). Combined with bleeding from another location (bruises, petechiae on the mucous membrane, vaginal bleeding).
- Idiopathic melena. Develops against the background of gastrointestinal bleeding of unknown etiology. Has a more favorable prognosis compared to the first form.
In newborns, false melena is distinguished when the stool turns dark due to nasopharyngeal bleeding or when swallowing maternal blood (cracked nipples, during childbirth).
Read more: Color of feces of a breastfed newborn: norm and pathology
When to see a doctor
Melena stool cannot occur on its own. In some cases, the patient needs to be urgently hospitalized. You need to visit a doctor if:
- the presence of bloody streaks in fecal matter;
- long course of the disease;
- the presence of a large number of additional signs;
- a sharp deterioration in health.
If you have any of the above symptoms, you should visit a doctor immediately. However, in their absence, it is prohibited to ignore the present symptoms. You need to see a doctor in any situation.
When visiting a doctor, the patient should be informed about the accompanying symptoms. In addition, it should be said about any medications taken. After this, the patient will be provided with referrals for diagnostic tests.
It is important to tell your doctor all your symptoms and complaints.
Dark and black stool - what tests should be done?
The appearance of black stools or the presence of blood during bowel movements is an indication for a more extensive diagnosis. First of all, it is necessary to check whether dehydrated stool depends on the presence of blood in the digestive tract.
To do this, a fecal occult blood test is performed. This is a non-invasive test that detects even small amounts of blood. There are two types of tests: the traditional guaiacol test and the tissue test. The first is more traditional, carried out in laboratory conditions, and the results are analyzed by specialists. However, a tissue test is available at pharmacies without a prescription and is self-administered. The next step is to perform laboratory tests, mainly blood tests.
In addition, if the occult blood test is positive, the doctor will order a colonoscopy (insertion of an endoscope with an optical fiber and camera into the colon through the anus) or gastroscopy (insertion of an endoscope through the cavity into the stomach through the esophagus).
Vorobyova Marina
Neurologist of the highest qualification category (work experience 14 years), doctor of neurofunctional diagnostics (work experience 12 years); author of scientific publications on vertebroneurology; participant of scientific conferences on neurology and functional diagnostics of all-Russian and international significance.
Tar stool - why is the color of the stool black?
Black stools are caused by chemical changes in hemoglobin, the red pigment in the blood. Blood and red blood cells are digested, i.e. red blood cells entering the gastrointestinal tract, for example, during gastric bleeding. This is the cause of black stools. And they can be loose, hard, compact.
As blood passes through the digestive tract, it is subjected to various chemical processes, primarily the action of intestinal bacteria, gastric juices and digestive enzymes. As a result of these processes, the feces become black. The stool may be hard and lumpy, but often when there is heavy bleeding it progresses to diarrhea as the blood speeds up the movement of the stool.
About
Tarry stool as a sign of normality
Sometimes black, tarry stools are normal. In this case, no special treatment is required. The condition normalizes on its own. The color of stool can change if:
- eating some fresh berries, such as blueberries and currants;
- the presence of beets in the diet;
- treatment of disorders with activated carbon or bismuth preparations.
When the stool is stained due to the consumption of beets, the feces change color only when there is an excessive amount of the vegetable in the diet. In this case, the urine becomes reddish. The feces become liquid because the product has a laxative effect.
When stool is stained by foods or drugs, the symptom does not require seeking medical attention. The condition is usually not accompanied by any additional symptoms.
