What Causes Black Tarry Stool?

Posted on Sat, 22 Apr 2017

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sat, 22 Apr 2017 Answered on

Sat, 13 May 2017 Last reviewed on

Question : I am undergoing treatment for vitamin deficiencies of B12 and D. I have had a recent colonoscopy that was clean. Tissues taken for biopsy were benign. Today, I had a thick, tarry black stool. Can that be coming from the vitamin deficiencies?Will it be ok to wait until Monday to see a medical professional about the bloody stool?

Answered by Dr. Grzegorz Stanko (27 minutes later)

Brief Answer:
You should not wait for it.

Detailed Answer:
Hello.

Thank you for the query.

The black tarry stool is a sign of stomach or small intestine bleeding. As you have also B12 deficiency, stomach inflammation or even a tumor is possible.

You should not wait for it. ER visit is advisable. Gastroscopy should be done as soon as possible.

Hope this helps. Let me know if I can assist you further.

Regards.

Above answer was peer-reviewed by : Dr. Arnab Banerjee