Black Stools

Have you ever glanced into the toilet and felt a jolt of concern at seeing black stools? This unexpected colour change can be alarming, leaving many to wonder about its significance. Black stools or melena often indicate an underlying health issue that requires attention. Understanding the causes behind this occurrence is crucial for maintaining good health and peace of mind. 

Black stools can stem from various sources, from harmless dietary choices to more serious medical conditions. Let's explore the potential causes of black stools, related symptoms, and diagnostic methods. 

Causes f Black Stools 

Black stools, also known as melena, often indicate a problem in the upper digestive tract. The following are some potential black stool reasons: 

Bleeding in the Upper Digestive Tract: The most common concerning cause of black stools is bleeding in the upper GI tract (the oesophagus, stomach, and the first part of the small intestine). When blood is exposed to gastric acids, it turns black and tarry, resulting in melena. Several conditions can lead to this type of bleeding: 

• Peptic ulcers 
• Oesophageal varices 
• Gastritis 
• Mallory-Weiss tear 
• Oesophageal and gastric cancers 

Dietary Causes: Certain dark-coloured foods can temporarily change the colour of stools: 

• Black liquorice 
• Chocolate sandwich cookies 
• Blueberries 
• Grape juice 
• Beets 

The dark colour typically disappears once the consumption of these foods stops.

Medications: Some medicines can cause black stools as a side effect: 

• Iron supplements 
• Bismuth subsalicylate medications 
• Activated charcoal 

Other Medical Conditions: Several other medical conditions can lead to black stools: 

• Unusual blood vessel formations in the oesophagus, stomach, or duodenum. 
• Ischaemia 
• Injury to the digestive tract or the presence of a foreign object can cause bleeding. 

Related Symptoms of Black Stools 

While the appearance of black, tarry stools is the primary symptom, individuals may experience a range of digestive symptoms, such as: 

• Abdominal discomfort or pain in the stomach area. 
• Nausea and vomiting, especially if there's bleeding in the upper digestive tract. 
• Heartburn or indigestion 
• Changes in bowel habits 
• Fatigue and generalised weakness 
• Dizziness or fainting, as severe bleeding, can lead to a drop in blood pressure. 
• In severe cases, unexplained weight loss 

Specific Symptoms Related to Causes

Depending on the cause of black stools, additional symptoms may be present: 

• If black stools are due to iron supplements, individuals might experience stomachache, nausea, constipation, and heartburn. 
• Bismuth subsalicylate medications can cause black stools and may also lead to a black tongue and a ringing or buzzing sound in the ears. 
• If a bleeding ulcer is causing black stools, individuals might feel worse overall and experience additional digestive discomfort. 
• In cases of bleeding from oesophageal varices, there might be bright red blood in the stools or vomit that looks like coffee grounds. 
• In the Mallory-Weiss tear condition, patients may experience additional symptoms like bright red vomit, weakness, dizziness, trouble breathing, pale skin, diarrhoea, and belly or chest pain. 

Diagnosis of Black Stools 

Doctors employ a comprehensive approach to diagnose the underlying cause of black stool, such as: 

• Medical History and Physical Examination 
  • Doctors ask detailed questions about recent dietary changes, medication usage, and known gastrointestinal conditions. This information helps rule out potential black stool reasons, such as consuming certain foods or medications containing bismuth. Following the medical history, the doctor focuses on signs of abdominal tenderness and other relevant findings. 
• Laboratory Tests: Doctors often order a series of laboratory tests to gather more specific data. These may include: 
  • Complete blood count (CBC) to detect the presence and severity of bleeding. 
  • A faecal occult blood test to detect hidden blood in the stool, confirming whether the black colour is due to bleeding or other factors. 
  • A stool culture to detect the presence of harmful bacteria or parasites 
  • Tests for Helicobacter pylori Infection 
• Imaging Studies: In many cases, doctors may advise the following imaging studies: 
  • Endoscopy: To examine the upper gastrointestinal tract, including the oesophagus, stomach, and duodenum. 
  • Colonoscopy: To examine the lower gastrointestinal tract, focusing on the colon and rectum. 
  • Upper Gastrointestinal Series: This X-ray examination visualises the upper digestive system. 
  • Angiography: To view blood vessels in the gastrointestinal tract. 
  • Capsule Endoscopy: This innovative method involves swallowing a small camera pill that captures images of the small intestine as it passes through. 

Treatment of Black Stools

The treatment of black stools depends on the underlying cause. Doctors focus on three main aspects: treating blood loss, stopping the bleeding, and addressing the root cause of the problem: 

• Assessing the Condition: When a patient presents with black stools, doctors assess their overall condition and tailor the treatment plan accordingly. These can include: 
  • Intravenous (IV) fluids to restore blood volume 
  • Blood transfusions for severe blood loss 
  • Intensive care for critical cases 
  • If black stools result from dark-coloured foods or iron supplements, limiting intake for a few days may resolve the issue. 
• Stopping the Bleeding: One of the primary goals in treating black stools is to stop active bleeding and prevent further blood loss. During an upper endoscopy, doctors can use various techniques to seal the wound and stop the bleeding: 
  • Electrocautery to seal the bleeding site 
  • Injection of medication into the wound 
  • Placement of clips or bands on blood vessels 
  • Stitching in some cases 
• Medication 
  • Depending on the cause of black stools, doctors may prescribe medicines, such as proton pump inhibitors (in case of ulcers, inflammation, or erosion in the gastrointestinal lining) and antibiotics (where infections are causing black stools). 
• Lifestyle Changes: Lifestyle adjustments can support digestive health and prevent the recurrence of black stools: 
  • Dietary adjustments to avoid foods that may irritate the digestive system 
  • Stress management methods to decrease the impact of stress on digestive health 
  • Regular exercise to promote overall well-being 

When to See a Doctor 

Melena can be a cause for concern, and it's crucial to know when to seek medical attention, such as: 

• If black stool has a sticky consistency and a strong, unpleasant odour 
• Vomiting blood or vomit that looks like coffee grounds 
• Feeling dizzy, weak, or lightheaded 
• Heart palpitations and shortness of breath 
• If black stools continue for more than a day or two 
• If an individual notices any amount of blood in their stool 

Prevention 

Preventing black stools involves understanding their potential black stool reasons and taking proactive steps to maintain digestive health. Here are some strategies to help prevent black stools: 

• If black stools appear after eating dark-coloured foods, they can limit their intake for a few days to see if it makes a difference. 
• Maintaining a balanced diet enriched in fibre, fruits, and vegetables supports overall digestive health. 
• Limiting triggering foods, spicy, fried foods, alcoholic beverages, and caffeinated drinks. 
• Medicines containing bismuth subsalicylate or iron supplements can turn stools black. Individuals should consult their doctor about safe alternatives or adjusting the dosage. Use NSAIDs only as directed or take them with food to reduce stomach irritation. Implementing stress-reduction practises such as meditation, yoga, or regular physical activity can maintain a healthy digestive system. 
• Quit smoking 

Regular check-ups and screenings can detect potential digestive issues early, particularly for individuals with a family history of gastrointestinal problems. 

Conclusion 

Understanding the black stool causes and implications has a significant impact on our approach to digestive health. From dietary influences to potential medical conditions, being aware of the various factors that can result in this symptom enables us to make informed decisions about our health. Maintaining digestive health involves a combination of mindful eating, proper medication management, and lifestyle choices. By staying vigilant about our body's signals and seeking professional advice when needed, we can take proactive steps to ensure our overall well-being. 

FAQ's 

1. What does a black stool indicate? 

Black stools, or melena, often indicate the presence of digested blood in the faeces. This symptom typically signals bleeding in the upper gastrointestinal (GI) tract, including the oesophagus, stomach, and duodenum. 

2. When should you worry about black stool? 

While black stools can have harmless causes, they should never be ignored, especially if they persist or are accompanied by other symptoms. Individuals should seek immediate medical attention if: 

• The black stools are tarry and have a strong, foul odour 
• The dark colour persists for more than two days 
• There's accompanying abdominal pain or discomfort 
• Other symptoms, such as vomiting of blood, dizziness, weakness, or shortness of breath, are present 

3. What are the symptoms that might accompany black stool? 

Various symptoms can accompany black stools, including: 

• Abdominal pain or discomfort 
• Nausea and vomiting 
• Heartburn or indigestion 
• Fatigue and weakness 
• Dizziness or fainting 
• Unexplained weight loss 
• Pale skin 
• Shortness of breath 

4. Can certain foods or drinks cause black stool? 

Certain foods and drinks can cause stools to appear black without indicating health concerns. Some common culprits include: 

• Black liquorice 
• Blueberries 
• Dark chocolate cookies 
• Grape juice 
• Beets 
• Blood sausage 
• Red wine 
• Iron supplements 
• Activated charcoal 

5. What colour stool is abnormal? 

While stool colour can vary based on diet and other factors, certain colours may indicate underlying health issues: 

• Black or dark brown: This can indicate bleeding in the upper GI tract or medications. Bright red or maroon: This might indicate bleeding in the lower GI tract, such as the large intestine or rectum. 
• White or clay-coloured: This could suggest liver or gallbladder problems. 
• Yellow: Very yellow stools might indicate an issue with fat absorption or a giardia infection. 

6. What vitamin deficiency causes black stool? 

Vitamin deficiencies do not typically cause black stools. In fact, it's often the treatment for certain deficiencies that can lead to this symptom. Specifically, iron deficiency anaemia and its treatment are most commonly associated with changes in stool colour. 

Dr. Snehal Makeshwar

MBBS, MD (Medicine), DNB (Gastroenterology), Fellowship in EUS
Ganga CARE Hospital Limited, Nagpur

To Book an Appointment, call:

+91 406 810 6585

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