Ask a doctor on the topic of Internal medicine

Blood in the stool or just discoloration?

July 31, 2016 | 30,00 EUR | answered by Dr. med. Frauke Gehring

Dear Sir or Madam,

this morning I had a somewhat harder stool that was partially dark brown (almost black). The toilet water turned red. It looked as if fresh blood had dissolved in the water.
I would like to mention that the day before I had eaten beetroot. Three years ago, I had a colonoscopy due to gas in the stomach, with negative results.
In May, I had a kidney MRI with contrast agent. They should have seen the lower kidneys and intestines, right? Again, the results were negative. Since my pregnancy (15 months ago), I have had hemorrhoids that I have not treated until today. I still experience extreme bloating, bowel movements sometimes several times a day, with quite large "portions".
I have had pain in my right kidney area for a few years.
My question is: should I be worried about the stool this morning and urgently see a doctor, or could the discoloration be due to the beetroot? In my opinion, it was not bloody stool. Can other organs and part of the intestines really be seen on a kidney MRI? I am currently abroad and will be back home on August 4th. What can I do about the bloating?

Thank you.

Dr. med. Frauke Gehring

Good day,

Tar-like stool would come from the stomach and would color the stool pitch black, not just partially brown/very dark. So, it was not tar-like stool. A red bleeding would come from the intestines, so it could have been caused by hemorrhoids (if irritated by hard stool). However, beets also color the stool red, making them the most likely cause of the discoloration.

If the colonoscopy was normal a year ago, bleeding tumors in the intestines are almost completely ruled out. They do not grow fast enough to cause noticeable bleeding after a year. Therefore, I believe it is absolutely reasonable not to immediately see a doctor.

The kidney MRI does not show the entire intestine, and certainly not small mucosal changes, but the colonoscopy is reassuring in this regard.

For bloating, fennel and caraway tea, chewing well, and supplements like Carmenthin N or Enzyme Lefax can help. Please also avoid bloating foods like cabbage or legumes.

Warm regards, Dr. Höllering