Melena: Overview
A feeling of being cold, but not necessarily in a cold environment, often accompanied by chills or tremors. The chills or tremors may have causes that are not due to an underlying disease. Examples include exposure to cold, fear, or nervousness.
Melena refers to Black colored stools that occur as a result of gastrointestinal bleeding. This bleeding usually comes from the upper gastrointestinal (GI) tract, which includes the mouth, esophagus, stomach, and the first part of the small intestine. Sometimes, bleeding in the ascending colon of the large intestine, located in the lower gastrointestinal tract, can also lead to melena.
Melena should not be confused with hematochezia, which refers to fresh blood in the stool that leads to brown or red stools. This blood usually comes from the lower gastrointestinal tract, most commonly from rectal bleeding, such as hemorrhoids.
Melena and hematochezia are symptoms, not actual conditions. Many conditions can cause both types of bleeding. Some of these conditions are serious, so it's important to see your doctor right away if you notice blood in your stool.
Causes
Although hematochezia and melena cause bloody stools, they each have different possible causes.
Hematochezia
- Hematochezia starts lower in your digestive tract, usually in your colon.
- Several factors can cause bleeding in the lower digestive tract, including:
- In children, hematochezia is commonly caused by IBD, Meckel's diverticulum, or juvenile polyps.
- In most cases, people can treat dehydration by drinking more clear liquids, such as water and herbal teas.
Melena
Melena is caused by bleeding higher up in your digestive tract. This may be due to:
-
Peptic ulcers
- Gastric or esophageal varices
- Gastritis
- Stomach cancer
- Mallory-Weiss syndrome
Some newborns get melena from swallowing blood during childbirth.
Diagnosis and Treatment
- Diagnosis or treatment begins with identifying the sources of bleeding to determine and treat the underlying cause. An assessment of the individual's medical history is done to identify related causes, such as chronic use of NSAIDs. Nasogastric lavage can be used to determine the severity of blood loss and to prepare the gastrointestinal tract for
endoscopy
, which is a minimally invasive procedure used to look inside the body. An upper endoscopy will often be done to determine the exact source of the bleeding.
- Drug treatment with proton pump inhibitors, such as esomeprazole or pantoprazole, can help reduce acid production, which promotes the healing of peptic ulcers and thus reduces the risk of recurrent bleeding. Proton pump inhibitors and antibiotics can also be used to treat helicobacter pylori infection, which is another possible cause of Malena.
- If necessary, the bleeding can be controlled with a combination of endoscopic therapies. The most commonly performed endoscopic therapy is injection therapy, in which the drug is injected directly into the source of the bleeding to encourage clotting. It is often combined with other endoscopic therapies, such as thermal techniques that apply thermal probes to cauterize the bleeding or mechanical techniques that apply pressure, using devices like clips or rubber band ligation.
- In some cases, an angiographic embolization may be performed, in which a drug or coils are placed on a guided catheter to block blood flow to the site of bleeding. Surgery may also be used to stitch ulcers or lacerations. Finally, severe cases may require blood transfusions.
When to visit a Doctor?
Severe rectal bleeding can constitute a medical emergency. Visit the emergency department if you experience one of the following symptoms:
- cold, clammy skin
- confusion
- continuous rectal bleeding
- fainting
- painful abdominal cramping
- rapid breathing
- severe anal pain
- severe nausea
