Why is My Poop Black? Common Causes, Treatment, and Prevention Tips


A man looking at the toilet

Discovering that your stool has turned black can be an unsettling experience that can raise concerns about your digestive health.

While many cases of black stool are benign, certain factors may indicate more serious health conditions that require professional treatment.

That’s why it’s important to understand why black stool can develop and when you might need to consult your doctor about it.

Keep reading to learn everything you need to know about black stool, including treatment and prevention tips for peace of mind.

Understanding Stool Color

Stool color can vary widely from person to person, depending on factors like diet, lifestyle, and overall health.

Normal or healthy stool colors usually range from shades of brown to slightly green. Your stool color may also be influenced by the bile produced in the liver.

Bile starts as green and gradually changes to brown during the digestive process, giving stool its typical color.

If the appearance of your stool changes drastically — for example, it turns black or red — this may indicate potential health issues.

Common Causes of Black Stool

Diet

Changes in your diet are usually the most common reason for black stool. Some dark-colored foods can naturally lead to darker stool, which is typically not cause for concern.

These foods may include:

  • Black licorice

  • Dark chocolate

  • Iron-rich foods like spinach, red meat, and lentils

  • Blueberries

  • Blood sausage

If you’ve consumed any of these foods in the past few days, it’s probably why your poop has turned black.

Your stool should return to its normal color once you eat less of these foods or eliminate them from your diet.

Medication

Various medications can affect your digestive system and cause black stool. These drugs may include:

  • Iron supplements: Taking iron supplements can cause temporary black stool when the mineral mixes with the microbiome in the digestive tract. Excess iron not absorbed by the body can also darken the stool.

  • Bismuth: This is a common ingredient in over-the-counter (OTC) stomach medications, such as Pepto-Bismol. Bismuth can temporarily darken the stool, but it should return to normal once you stop taking the medication.

If your doctor has prescribed these medications to treat underlying conditions — such as anemia or stomach issues — consult them if you’re experiencing black stool. Often, it’s a normal side effect, but a dosage adjustment can minimize the risk.

You should stop taking the medications immediately if you:

  • Have a ringing or buzzing in your ears or you can’t hear

  • Feel worse after using the medications

These symptoms could indicate that the drugs are too potent for your condition and you may require alternative treatment options.

Gastrointestinal bleeding

If you are passing black stool without changes to your diet or medication, this may be a sign of upper gastrointestinal (GI) bleeding.

This is an emergency medical situation that requires immediate care to prevent potentially life-threatening complications.

There are various causes of bleeding in the upper GI tract, including:

Peptic ulcers

These sores form on the stomach lining or small intestine and can start to bleed.

When the blood interacts with gastric acids, it turns black, altering the stool's color. If you have a peptic ulcer, you may also experience symptoms like:

  • Burning pain in your belly

  • Swelling or bloating

  • Burping

  • Heartburn

  • Nausea

  • Vomit that looks like coffee grounds

Factors like chronic stress, excessive drinking, and prolonged use of anti-inflammatory medications can cause peptic ulcers.

Gastritis

Gastritis occurs when the stomach lining becomes inflamed. If left untreated, this can cause bleeding in the digestive tract, which can lead to black stool.

Common causes of gastritis include:

  • Prolonged use of certain medications, including aspirin, ibuprofen, or naproxen

  • Excessive alcohol consumption and drug use

  • Stomach infections called Helicobacter pylori (H. pylori)

  • Autoimmune diseases

  • Bile reflux

  • Extreme stress

  • Viral infections, such as herpes or cytomegalovirus (CMV)

If you suspect that you have gastritis, speak to your doctor as soon as possible to discuss your treatment options.

Other causes

Gastrointestinal bleeding can also be caused by other underlying factors, such as:

  • Esophageal varices: These are swollen veins in the esophagus that can burst and bleed.

  • Mallory-Wiess tears: These are tears that develop in the esophagus due to excessive vomiting. This can cause bleeding, which may leak into the digestive system.

Consult your doctor if you suspect that you have any of these conditions to prevent further complications.

Other possible causes

While less common, there are also other potential causes for black stool, such as:

  • Heavy metal poisoning: Prolonged exposure to heavy metals like lead or bismuth can cause black stool. This is rare and often associated with industrial occupations or accidentally consuming contaminated substances.

  • Health conditions: Certain health conditions — such as liver disease or inflammatory bowel disease (IBD) — can indirectly lead to black stool by causing gastrointestinal bleeding.

  • Cancer: Gastrointestinal cancers, including stomach and colorectal cancer, may cause internal bleeding, resulting in black stool. This is typically accompanied by other symptoms, such as unexplained weight loss, fatigue, and changes in bowel habits.

These are typically considered only after excluding factors such as changes in diet or medication, and gastrointestinal bleeding from peptic ulcers or gastritis.

What are the Treatment Options for Black Stool?

Dietary adjustments

If your black stool is caused by dietary factors, making specific adjustments can help restore a normal color and consistency. These changes may include:

  • Avoiding foods known to darken stool: Reducing or eliminating foods that can cause black stool — such as licorice, dark chocolate, or blueberries — can help.

  • Modifying iron intake: If high levels of dietary iron or iron supplements are the cause, adjusting the intake could help prevent black stool. This might mean switching to a different iron supplement or adjusting the dosage.

Managing underlying conditions

For black stool caused by underlying health conditions, your treatment will typically focus on addressing that issue and managing any other symptoms.

Common conditions and their treatment options may involve:

  • Peptic ulcers and gastritis: These conditions are often treated with medications — such as proton pump inhibitors (PPIs) or H2 blockers — to reduce stomach acid and promote healing. Antibiotics may also be prescribed if an H. pylori infection is causing your black stool.

  • Esophageal varices: Treatment for these esophageal tears may include medications and procedures to band the varices. In severe cases, surgery may be recommended.

  • IBD: Treatment options for IBD usually include anti-inflammatory drugs, immune system suppressors, and sometimes surgery to remove damaged portions of the gastrointestinal tract.

  • Liver disease: Managing liver disease involves a combination of lifestyle changes and medication to manage symptoms. In some cases, surgical interventions may be considered to slow disease progression.

Medical treatments

Black stool caused by a more serious condition — such as upper gastrointestinal bleeding — may require more intensive medical treatment to resolve the issue.

For gastrointestinal bleeding, immediate treatment to close the wound or source is crucial.

Your doctor will recommend the most appropriate option after performing an evaluation and making a diagnosis.

This might involve endoscopic procedures to locate the bleeding source, followed by banding or the application of clips to seal it.

In some cases, more extensive surgical procedures may be required.

If cancer is the underlying cause of black stool, treatment options may include tumor excision, chemotherapy, or radiation.

Depending on the stage of the cancer, your doctor may recommend a combination of treatments to manage your condition.

Can Black Stool Be Prevented?

Tips for monitoring stool health

Keeping an eye on your stool can help you gain a better understanding of your digestive health and help prevent black poop from occurring.

Understanding which warning signs and symptoms to look out for allows you to know when it is necessary to seek professional help.

A few useful tips for monitoring and maintaining your stool health include:

  • Paying attention to changes: Regularly observe the color, consistency, and frequency of your stool. Sudden changes or persistent irregularities can be an early indicator of health issues.

  • Keeping a food diary: Tracking what you eat can help identify if your dietary habits are influencing stool color. This is especially helpful if you're trying to determine if specific foods are causing black stool.

  • Staying hydrated: Adequate hydration is important for maintaining healthy bowel movements. Dehydration can lead to constipation, which can affect stool color and health.

  • Following a fiber-rich diet: A diet high in fiber can help ensure smooth digestion and regular bowel movements, which can help maintain normal stool color and prevent constipation.

If you notice anything that prompts concern, schedule an appointment with your doctor as soon as possible to ensure peace of mind.

When Should You See a Doctor About Black Stool?

While black stool isn’t always cause for concern, it’s important to know when to see your doctor for a professional diagnosis.

You may require immediate medical attention if you experience any of the following symptoms:

  • Black and tarry stools with a foul smell

  • Additional symptoms like abdominal pain, dizziness, and fatigue

  • Vomiting blood

  • Black stool that lasts for more than three weeks

You should also speak to your doctor if you have a personal or family history of digestive disorders or any questions or concerns about your digestive health.

Where Can You Learn More About Bowel Health?

If you’re concerned about black stool or want to know more about maintaining digestive health, LifeMD is here to help.

A team of medical professionals can assist you with information and provide guidance on improving bowel health to prevent any complications.

Make an appointment with LifeMD today to learn more about bowel system care — all from the comfort of your home.

LifeMD makes it easy to stay on top of your health because talking to a doctor, filling your prescriptions, getting your labs done—and more—are all easy and cost-effective. Come discover a healthcare solution built around you and your life.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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