Black Stool: Causes and When to Seek Medical Attention

Q: Black Stool: Causes and When to Seek Medical Attention

Hello： A stool occult blood test can determine if there is any bleeding. <br>Black stools, on the other hand, should raise concerns about upper gastrointestinal issues. <br>Changhua Hospital cares about your health. <br>Dr. <br>Tsai An-shun.

Black stool

Hello Doctor, I am 20 years old.
Recently, I have had black stools for two consecutive days.
Yesterday, the stool was dark brown, close to black, and today it is considered black.
Neither day was the entire stool completely black; yesterday's was half black and half brown, while today's is half black and half dark brown, with a bit of dark green.
The black portion is in the front half and is drier and harder, while the other part is softer.
My diet has been normal these past few days, but I have been taking a blood supplement called Mei Yan Si Wu Iron, although I only take 35 ml at a time, once a day.
I also take probiotics, one capsule a day.
Additionally, I have been taking Jingtian Gaslang tablets and Macolon Fudaning tablets (because a doctor previously diagnosed me with irritable bowel syndrome).
For the past few days, I have been experiencing pain in the lower left abdomen; sometimes it is a slight stabbing pain that lasts a few seconds, and other times I feel pain when bending over, but it goes away when I stand up straight.
Furthermore, my bowel movement frequency used to be once every three days, but since early September (possibly due to taking traditional Chinese medicine, which I have now stopped for about three to four days), it has changed to once a day.
I am very worried about this change in my bowel habits and concerned it might be colon cancer.

Jane, 20~29 year old female. Ask Date: 2020/10/26

Dr. Cai Anshun reply Gastroenterology and Hepatology

Hello: A stool occult blood test can determine if there is any bleeding.
Black stools, on the other hand, should raise concerns about upper gastrointestinal issues.
Changhua Hospital cares about your health.
Dr.
Tsai An-shun.

Reply Date: 2020/10/26

More Info

Black stool can be a concerning symptom, and it's understandable that you're feeling anxious about it, especially given your recent changes in bowel habits and abdominal discomfort. Let's break down the potential causes of black stool and when you should seek medical attention.

Causes of Black Stool
1. Dietary Factors: Certain foods can lead to dark-colored stools. For example, consuming foods rich in iron (like red meat or iron supplements) or foods with dark pigments (like blueberries or black licorice) can cause your stool to appear black or very dark brown. Since you mentioned taking iron supplements, this could be a significant factor in the color change.

2. Medications: Some medications, particularly those containing bismuth (like Pepto-Bismol), can also cause black stools. You mentioned taking various medications, including those for gastrointestinal issues, which could potentially contribute to this symptom.

3. Gastrointestinal Bleeding: One of the more serious causes of black stool is gastrointestinal bleeding, particularly from the upper GI tract (such as the stomach or duodenum). When blood is digested, it can turn black, leading to a condition known as melena. This is often accompanied by other symptoms such as abdominal pain, nausea, vomiting (possibly with blood), or weakness.

4. Other Medical Conditions: Conditions such as peptic ulcers, gastritis, or esophageal varices can lead to bleeding in the gastrointestinal tract, resulting in black stools. Your mention of left lower abdominal pain could be related to various gastrointestinal issues, including irritable bowel syndrome (IBS), which you have been diagnosed with.

When to Seek Medical Attention
Given your symptoms, there are several indicators that warrant a visit to a healthcare professional:
- Persistent Black Stool: If the black stool continues for more than a couple of days, it’s essential to seek medical advice.

- Accompanying Symptoms: If you experience additional symptoms such as severe abdominal pain, vomiting (especially if it resembles coffee grounds), dizziness, or weakness, you should seek immediate medical attention.

- Changes in Bowel Habits: Since you have noted a change in your bowel habits, such as increased frequency and the nature of your stool, it’s important to discuss these changes with a healthcare provider.

- Concerns About Cancer: While it’s understandable to worry about serious conditions like colorectal cancer, especially with a family history or other risk factors, it’s crucial to discuss these concerns with a doctor who can evaluate your symptoms and possibly recommend screening tests.

Conclusion
While dietary factors and medications are common causes of black stool, the presence of abdominal pain and changes in bowel habits should not be overlooked. It’s advisable to consult with a healthcare professional who can perform a thorough evaluation, including a physical examination and possibly diagnostic tests like blood work or imaging studies, to rule out any serious conditions. Early intervention is key in managing any potential health issues, so don’t hesitate to reach out to a doctor for peace of mind and appropriate care.

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