
Dark stools could be due to minor causes, such as dietary changes, or medications, such as iron supplements. However, some underlying conditions, such as intestinal bleeding, may result in dark brown or black stools.
What are the causes of dark stools?
Foods that cause dark-colored stools
Foods that cause dark-colored stools include:
The color of the stools after taking these foods is generally dark brown, bluish, reddish, and black. The stool color should change to the usual when you stop taking those foods.
Medications that result in dark-colored stools
- Iron supplements
- Antidiarrhea medications, containing bismuth subsalicylate
Dark brown stools could be sometimes because of bleeding in the digestive tract. The color and quality of the poop usually depend on the site of bleeding and the movement of stool through the digestive tract.
- The black color stools with sticky consistency are due to the bleeding in the esophagus, stomach, and small intestine.
- Bright red stools are due to bleeding in the lower digestive tract, especially from the colon and the anus.
- Red stripping over the stool is due to the hemorrhoids in the digestive system's exit.
When dark brown stools are due to bleeding in the digestive tract and factors, such as medications and foods, are ruled out, immediate medical care should be sought.
What digestive conditions cause dark stools?
Dark stools may occur due to:
- Intestinal ulcers
- Gastrointestinal cancers
- Anal fissure
- Atrophic gastritis
- Bacterial or viral infection of the gastrointestinal tract
- Colitis
- Diverticular disease
- Gastroesophageal disease
- Inflammatory bowel disease
Here are some serious causes of dark stools, which should not be ignored and need medical attention.
Bleeding ulcer
Bleeding or a wound on the inner lining of the stomach or intestine. When the blood is exposed to gastric acids, that turn stools black and sticky. This is called melena. It is a sign of upper gastrointestinal bleeding.
Alcohol consumption and excess intake of nonsteroidal anti-inflammatory drugs result in gastrointestinal bleeding.
Other signs of intestinal bleeding are:
Esophageal and gastric cancers
Any benign or malignant tumor on the gastrointestinal lining results in the rupture of the intestinal lining and leads to bleeding. The blood gets combined with gastric juices and causes dark and sticky stools.
Other symptoms of esophageal cancers include:
- Difficulty swallowing
- Indigestion or heartburn
- Weight loss
- Chest pain
- Coughing
Other symptoms of gastric ulcers:
- Fatigue
- Bloating after eating
- Severe heartburn and indigestion
- Weight loss
- Abdominal pain
Esophageal tearing
Severe coughing results in esophageal tearing called Mallory-Weiss tear, resulting in bleeding.
Other symptoms of Mallory-Weiss tear include:
- Abdominal or chest pain
- Bright red or dark vomit
- Weakness
- Dizziness
- Pale skin
- Diarrhea
- Difficulty breathing
Esophageal varices
The swollen veins in the esophagus are called esophageal varices. These varices break open and lead to bleeding, which causes dark stools. These abnormal veins are most seen in people with liver diseases.
Other symptoms of esophageal varices:
Other life-threatening causes of dark stools
- Bleeding disorders
- Perforated peptic ulcers
- Diverticulitis

SLIDESHOW
Super Tips to Boost Digestive Health: Bloating, Constipation, and More See SlideshowHow is the cause of black stools diagnosed?
If the symptoms are severe, visit a doctor immediately. They may ask you about the signs and history of the condition. Then, your doctor may do a physical examination and order several blood and stool tests.
A few diagnostic imaging, such as colonoscopy or gastroscopy, are done to check the condition of your digestive tract.
- Colonoscopy is done under sedation, and your doctor will insert a flexible tube into the anus with a camera attached to see the inside of the colon and look for the cause of symptoms.
- Gastroscopy is like a colonoscopy, but the flexible thin tube is inserted through the throat with a camera attached to it. It helps identify lumen or abnormalities in the innermost layers of the esophagus, stomach, and small intestine.
What treatments are suggested for black stools?
Treatment of black stools depends on the underlying cause, but may include:
- If the cause of the dark stools is due to foods or medications, immediately stopping those foods and drugs helps get normal stools.
- If the cause of black stools is gastrointestinal ulcers, the proton inhibitors and ulcer protective agents may help treat black stools.
- The decreased usage of nonsteroidal anti-inflammatory drugs, steroids, and spicy foods may help reduce intestinal ulcers.
- Surgery is recommended in severe cases of intestinal ulcers that do not respond to medical therapy, have perforated, or are a result of a tumor in the gastrointestinal area.
Why Is Your Poop Black and Tarry? https://www.webmd.com/digestive-disorders/black-tarry-stool-reasons
Black or tarry stools. https://medlineplus.gov/ency/article/003130.htm
Rectal Bleeding. https://my.clevelandclinic.org/health/symptoms/14612-rectal-bleeding
Top Why Is My Poop Dark Brown or Almost Black Related Articles
Can You Still Poop With Impacted Feces?
Digestion is the process of breaking down food in the gut so that it is in easily absorbable forms. The food travels from the mouth to the food pipe, stomach, small bowel, and large bowel to be finally eliminated through the anus. The small bowel (small intestine) absorbs nutrients from the food.Diarrhea
Diarrhea is a change in the frequency and looseness of bowel movements. Symptoms associated with diarrhea are cramping, abdominal pain, and the sensation of rectal urgency. Causes of diarrhea include viral, bacterial, or parasite infection, gastroenteritis, food poisoning, and drugs. Absorbents and anti-motility medications are used to treat diarrhea.Digestive Disorders: Why Do I Have Blood in My Stool?
Do you have blood in your stool? Find out about possible causes and what steps you should take.Diverticulitis (Diverticulosis)
Most people with diverticulosis have few if any symptoms at all. When people do experience signs and symptoms of diverticulosis (diverticular disease) they may include abdominal pain, abdominal cramps, diarrhea, constipation, and bloating. Diverticulitis is a condition in which diverticula in the colon rupture. The rupture results in infection in the tissues that surround the colon. Treatment methods for diverticulitis include prescription medications, and in some cases, diverticulitis surgery.Intestinal Gas and Gas Pain
Intestinal gas and painful bloating are common. Learn about what causes gas pain and how eliminating certain foods from your diet can help relieve symptoms.Is Green Poop a Sign of Infection?
Green poop may or may not be a sign of infection. The normal color of poop is brown, due to the bile pigment present in it. Any other color (green, red, black) needs attention. Abnormal colored poop may be due to changes in food habits, medicines or underlying medical causes.Stool Acidity Test
A stool acidity test diagnoses lactose intolerance. During a stool acidity test, the patient is given lactose to drink. In people who are lactose intolerant, some or all of the lactose is not digested and absorbed in the small intestine and reaches the colon. This causes the stool to become acidic. The acidity of stools that are passed after ingestion of the lactose then is measured.Stool Color, Changes, Texture and Form
Stool color changes can very from green, red, maroon, yellow, white, or black. Causes of changes of stool color can range from foods a person eats, medication, diseases or conditions, pregnancy, cancer, or tumors. Stool can also have texture changes such as greasy or floating stools. Stool that has a uncharacteristically foul odor may be caused by infections such as giardiasis or medical conditions.The Truth About Poop: Test Your IQ
Everyone does it, but no one talks about poop! What do changes in your poop mean? Take this quiz to learn about how your body functions!What Should I Do If My Poop Is Green?
Learn why your poop is green and what you can do to treat it. Black, bright red, and pencil-thin stools are red flags for colon cancer. Other signs and symptoms of colon cancer include changes in bowel habits such as diarrhea and constipation.When Is Green Poop a Sign of Infection?
Green poop is a common issue, but sometimes it's a sign of infection. Learn green stool's signs, causes, and treatment options. Black poop is usually a common condition, but may signify underlying medical conditions.Why Is My Poop Green?
Green stools are a common condition that affects many people. Learn the signs of green stools, what causes them, how doctors diagnose them, and what you can do to treat it.