My stools appear black despite stopping iron supplements. Why?

Q. Can stool appear black despite stopping iron supplements?

Answered by
Dr. Goswami Parth Rajendragiri
and medically reviewed by iCliniq medical review team.
This is a premium question & answer published on Jan 19, 2023 and last reviewed on: Oct 16, 2023

Hello doctor,

I have had iron deficiency anemia for three months. In short, my third CBC doctor said everything is going fine, and my hemoglobin level is increasing. I have also done another blood test, even if I have not used iron supplements for two days. My blood levels were still increasing; I asked the doctor about losing my appetite and if my iron deficiency was the cause of my stomach bleeding. And he said I had to have a coffee-like stool or vomit.

Later that day, when I woke up, my lower abdomen was gurgling so much (with no pain), and I went to the toilet; that was some liquidy stool (or tarry), and I had not used iron supplement for one, and half days though it was still black (One day ago, I only took 5 mg, and the other day when I check my CBC I did not take my iron supplements at all as I forgot to take me with them)

If I had gastrointestinal bleeding, would it show up in CBC? And how long does iron supplement stay in the body?

Is it normal for my stool colors to be black even though I have not taken them for a day?

Kindly advise.



Welcome to

If you have significant gastrointestinal bleeding, it is reflected in CBC (complete blood count) in the form of decreased hemoglobin level and increased platelet count. However, the minor bleeding will not be reflected in CBC.

Iron medicine can remain in circulation for one day. So your black stool could be because of that. But still, after two more days, if your stool remains black, then investigate with stool routine micro examination and occult blood test. An occult stool blood test will detect any minor bleeding also if present. Your upset stomach could be because of an iron tablet.

I hope I have solved your query.

Thank you.

Was this answer helpful?


Same symptoms doesn’t mean you have the same problem. Consult a doctor now!

Related Questions:
I am passing black stools since two days. Why?

.. Irozorb can make the stools black or it may be happening due to gastritis or stomach ulcers. It is the iron that oxidizes and give black color, but it seems like you are taking these medications since four months.   Read full

I have fever and gurgling sensation near the liver area. Please advise.

You have low hemoglobin and low T4 which meant you are having iron deficiency and your dose of Thyronorm is low although TSH is normal   Read full

Could gastritis cause black stools?

.. here to help you. Most likely you are being given steroids or painkillers in the form of herbal supplements, and they have the side effect of gastritis that can cause black stools. Black stools can also be caused by multivitamins.   Read full

Also Read Answers From:

ideaComprehensive Medical Second Opinion.Submit your Case

Also Read

PCOS and Liver Problems
The hormonal imbalances in polycystic ovary syndrome could cause liver diseases. Read the article to know the relationship between these medical conditions.  Read more»
Inferior Alveolar Nerve Lateralization Technique
The inferior alveolar nerve lateralization technique is a surgical lateralization technique to reposition the nerve. Read the article to know more about this.  Read more»
COVID-19 and Ebola: Similarities and Differences
This article gives a comparison and broader overview of the outbreak of the two deadliest diseases that showed a greater incidence over the last two decades.  Read more»

Ask your health query to a doctor online?

Ask a Hematologist Now

* guaranteed answer within 4 hours.

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.