Melena is the term used for black coal tar colored stool. It is caused due to passage of blood in stool. When iron from hemoglobin gets decomposed in intestine while passing through, it gives dark black color to the stool.
Melena is an abnormal condition caused when there is bleeding from upper gastrointestinal region i.e. stomach and duodenum. The lower intestine hemorrhage is usually bright red. It is the first sign of upper gastrointestinal bleeding, which is important for diagnosis of disease such as peptic ulcer.
Melena Symptoms
Symptoms of melena or blood in stool:
- Patient complains change of stool color to his medical attendant; it is dark black like coal tar.
- Anemia is most important sign noted in patients with melena.
- Weakness.
- Breathlessness.
- Pain in abdomen, due to peptic ulcer.
Causes Of Melena
Black stool or melena causes include:
- Peptic ulcer that includes stomach ulcer, duodenal ulcer.
- Stomach cancer.
- Patient on anti-coagulant drugs such as Warfarin may cause melena.
- Gastritis (inflammation of stomach) and esophageal varices.
- Hemorrhagic blood disease such as purpura.
- Swallowed blood as in case of nose bleeding can also give rise to melena.
- Intestinal worms.
Functional causes of melena with no significant clinical importance are supplementary iron consumption.
Infants may present with melena after birth, due to swallowing of maternal blood during delivery.
Treatment For Melena
- Diagnosis of disease after patient having melena is important. For this laboratory stool examination, upper GI endoscopy and barium X-ray helps the medical attendant to find the cause.
- Treatment will depend on the cause. In case of peptic ulcer, conservative line of treatment will heal the ulcer, bland diet, medications for H.pylori infection will cure melena.
- Gastric cancer will need more invasive therapy such as operation.
- Esophageal varies will require banding.
- If worms are involved, patient has to be dewormed with medications.
Diagnosis of peptic ulcer
Examination of blood – hemoglobin level will be low in patients with chronic blood loss (melaena and/or hematemesis). A raised ESR in gastric ulcer suggests malignancy.
Examination of stool - occult blood in the stool may be detectable in all cases of active ulcer due to oozing of blood from the ulcer as both stomach and duodenum have enormous blood supply. In case of melaena the stool becomes black and tarry as the blood during its passage through the intestine becomes partially digested and altered.
Gastric function tests – these tests are performed as first things in the morning and are comprised of basal secretion and maximum secretion by stimulants such as insulin, histamine and pentagastrin.
Radiological investigations – Barium meal X-ray is often diagnostic in peptic ulcer. In case of gastric ulcer a niche or ulcer crater will be seen projecting from the smooth outline of stomach. In some cases there will be a constant notch on the greater curvature just opposite the position of the ulcer. This is due to local spasm of the circular muscles. Barium X-ray also gives a clue to differentiate between benign ulcers the ulcer crater penetrates beyond the projected line of the wall of the stomach, but in malignant ulcer erosion into a filling defect that protrudes into the stomach in detectable. In duodenal ulcer 75% to 80% cases can be diagnosed accurately by barium meal X-ray. A normal duodenal bulb is rounded and full. In case if ulcer disease, there is irritability and the bulb becomes difficult to fill with contrast medium. Demonstration of ulcer crater itself is the positive evidence of an active ulcer.
Secondary radiologic signs are mucosal edema and spasm. Mucosal edema will cause widening radiolucent folds clearly demarcated by barium lying in the crevices.
More on treatment for duodenum cancer
Endoscopy – development of fiber-optic pan-endoscope has greatly facilitated diagnosis of peptic ulcer disease. Diagnostic accuracy is 95% or more and the evidence is clear that endoscopy is superior to radiography in defining presence of lesion in the esophagus, stomach and duodenum. By endoscopy the whole of the interior of the stomach can be adequately inspected. By this endoscope one can clearly inspect the inside of esophagus, stomach and duodenum. Addition of the gastro-camera will allow taking pictures of the inside views.
Indications of Peptic Ulcer
- In the diagnosis of shallow gastric or duodenal ulcer which is not visualized by barium meal X-ray.
- In undiagnosed dyspepsia.
- In checking results of medical treatment.
- To differentiate chronic peptic ulcer from carcinomatous ulcer.
- Its value is perhaps greatest in bleeding patients, either from esophageal varices or from ulcers.
- In demonstrating acute mucosal erosions.
- Related Topics
- Black Stool Causes, Treatment | Dark Colored Feces Prevention
- Black Spots in Stool Causes: Treatments for Small Black Spots in Stool
- Travel Sickness Symptoms | Kinetosis, Black Stool Diet, Remedy
- Dark Colored Feces, Stool or Poop: Causes, Home Remedy for Dark Stool
- Difficulty Passing Stool: Causes, Treatment For Problem To Pass Stool
