The color of normal stool is brown which signified presence of bile in stool. Bile is made by liver but it is concentrated and stored within the gallbladder before it is secreted into intestine where it aids in digestion of food. The stool released by adults may appear black or dark because of ingesting substances or medicines with iron or it may be caused by serious conditions involving bleeding of digestive tract.
Having black stool in adults may not necessarily mean that there is a dangerous condition but in other times, it may implicate a condition like peptic ulcer that causes bleeding in digestive tract. There are many reasons why stools could appear black and with foul smell such as taking foods that contain iron supplements. But when the black color is caused by bleeding, it means that blood is being released at some point within the upper gastrointestinal tract.
Black or tarry stool occurring due to presence of blood is referred to as melena but a false melena may occur when the black or dark color is not from blood. When you have black stool that appears tarry in texture and releases foul smelling, it may be a symptom of bleeding within the upper gastrointestinal tract such as the esophagus, the stomach, or the small intestine.
Having a rectal bleeding containing bright red blood with some clots, which are at times mixed with stool, is known as hematochezia. This is often caused by lower digestive tract bleeding such as the colon, anus, or rectum. If there is small amount of blood within stool that may be visible to the eye but does not cause a considerable change in color of the stool, this may be referred to as fecal occult blood and it could be a symptom of quite serious disease.
Releasing black bowel movement shows symptoms of serious conditions like esophageal varices and peptic ulcers. You should seek prompt medical attention when you have unusually dark stool or change in texture or other colors. A black stool that is not attributed to food or taking of iron supplements should be treated seriously and one ought to see a physician immediately. When the black color of stool is accompanied by other signs and symptoms such as acute pain and vomiting, ensure you seek immediate medical attention.
Causes of black stool in adults
Black stool may be caused by different factors ranging from diseases, infections, trauma, malignancy, inflammation, to iron supplements and foods. The common causes are associated with stomach ulcers or peptic ulcers, and the inflammation of gastrointestinal tract from use of nonsteroidal anti-inflammatory drugs including aspirin and ibuprofen.
People need to differentiate between signs of bleeding occurring within the upper gastrointestinal tract and that from lower gastrointestinal tract. When the bleeding is occurring from the upper parts of gastrointestinal tract like stomach and esophagus or small intestines, the stool appears black with a tarry texture. But the bleeding arising from lower parts of the tract, the color is usually red or maroon.
The conditions, which may cause black stool, are such as esophageal and abdominal trauma, bleeding peptic ulcers, or abnormally distended or widened blood vessels in esophagus that break and release blood, a condition known as esophageal varices bleeding. Other conditions are such as bowel ischemia or lack of normal flow of blood to intestines or death associated with intestinal tissue.
NSAIDs may cause gastritis, which brings about irritation and swelling of stomach. Inflammatory bowel disease including ulcerative colitis and Crohn’s disease may also cause the upper part of gastrointestinal tract to bleed. Cancer of the stomach and upper gastrointestinal tract could also cause the stool to appear black because of bleeding.
Apart from these conditions, black tools may also be caused by medicines and foods taken by an individual. Medicines that contain bismuth, iron supplements, and black licorice are also possible causes of black stool.
Symptoms that might accompany black stool
The symptoms accompanying black tool may depend on the underlying condition, disorder, or disease. These symptoms include diarrhea, change in bowel movement, indigestion, gas, or flatulence.
A person may also have cramping or abdominal pain, poor appetite, vomiting, nausea, and flu like symptoms including sore throat, fever, aches, coughs, pains, and fever. Unexpected weight loss, and foul smelling stool are other symptoms that may come with black stool.
When to seek medical help
If you are releasing black stool with tarry texture without having taken some medicines or food rich in iron or iron supplements, you might want to seek medical help. If the stool color is accompanied by other symptoms like cramps and pain or fever, you might also want to see a doctor. Tests may be performed to rule out the possibly of having a serious gastrointestinal condition that may be causing bleeding especially on the upper part of the gut.