What Causes Black Stool

Going to the toilet for bowel evacuation is a daily morning chore. We all hope to have a smooth bowel movement and good digestive health but if fecal defecation produces black tarry stools, then it is indeed a cause for concern. Excretion of black stools points toward internal bleeding. When blood comes in contact with stool, it is observed that stool color changes to black.

Causes

Internal Bleeding
Internal bleeding may occur due to wide number of health issues that are often related to the stomach and the intestines. The most common causes of internal bleeding are given below:

Stomach Ulcers
As we all know ulcers are open wounds that bleed profusely when touched. Stomach ulcers erupt on the lining of the stomach and bleed. The blood then moves through the colon and eventually mixes with the stool, leading to black defecation.

Anal Fissures
This is a painful condition associated with the anal canal. As we all know, the anal canal that lies between the anus and the rectum, has a length of 2.5 to 4 cm. The anal canal is a passage from where the stools are thrown out of the body. In this condition the lining of the anal canal gets damaged. To be more specific, it is torn and hence when hard stools pass through the anus, it causes further damage to the lining of the canal. This may lead to bleeding and is seen in the form of black stools.

Hemorrhoids
When the veins that are located inside the anal canal get swollen, the condition is referred to as hemorrhoids. In such cases, the inflamed veins may rupture during bowel evacuation. This bleeding in the rectal area ultimately leads to black bowel movement.

Diverticulitis
This is a term used to describe the inflammation of the diverticula. The large intestine is a long tubular structure where digestion takes place. Over time, sacs (pouches) protrude out of colonic wall. This abnormal bulging mass that is observed at different points on the intestinal wall is referred as diverticula. When these diverticula are invaded by a bacterial infection, they may rupture. The rupturing of the diverticula eventually triggers bleeding from rectal area and causes defecation of black stools.

Colon Cancer
Development of tumors in the colon that eventually become cancerous is one of the causes of black bowel movement. Tumors are nothing but abnormal protruding mass of tissue, resulting from indiscriminate division of cells. In most cases, tumors in the colon bleed and cause painful black bowel movement. Colon cancer is a serious issue and requires urgent treatment.

Intake of Iron Rich Foods
Eating certain foodstuffs can also lead to black bowel movement. In such cases, change in stool color is not a cause for worry and doesn't require any visit to a doctor. Treatment generally involves minimizing the intake of these foods. So, which are the foods that give rise to black stools? Foods high in iron are the main culprits that make the stools black. People having too much intake of iron rich foods on a daily basis, produce black tarry stools. Some of the foods considered to be a good source of iron are given below:

• Dark green leafy vegetables such as legumes and spinach
• Fruits such as bananas, cherries, figs, blueberries and plums
• Red meat, chicken and egg yolk

The doctor may perform a colonoscopy in which a long tub (colonoscope) attached with a small camera, is slowly inserted through the anus until the doctor gets a clear view of the large intestine. The attached camera to the colonoscope provide in-depth visual inspection of the colon, thus allowing the doctor to detect any abnormality.