Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
What Causes Dark Tarry Stool?
Question: I'm curious if starting probiotics can cause stool color to change. my husband started them a week ago and immediately his stool turned a very dark brown. not black and tarry but very dark brown. normal movement, no changes in that, just the color. he has taken 4 of the probiotic chewables in the last 7 days. he stopped two days ago and his stool this morning is still dark brown. borders on black, but not black. he does not take iron, has taking no pepto bismol or eaten licorice, berries or drank red wine
Brief Answer:
a possible effect of probiotics
Detailed Answer:
Hi and welcome,
Yes, stool color change may be caused by probiotics and this may persist for up to 5 days after last probiotics intake. other causes include some dietary changes, liver issues or chronic gastrointestinal bleeding. however, at this point you should just wait for few days, have easier diet and more fluids and see will normal color come back. If not, then colonoscopy should be done.
Wish you good health. Regards
a possible effect of probiotics
Detailed Answer:
Hi and welcome,
Yes, stool color change may be caused by probiotics and this may persist for up to 5 days after last probiotics intake. other causes include some dietary changes, liver issues or chronic gastrointestinal bleeding. however, at this point you should just wait for few days, have easier diet and more fluids and see will normal color come back. If not, then colonoscopy should be done.
Wish you good health. Regards
Above answer was peer-reviewed by :
Dr. Prasad
thank you so much. I did have a picture but the lighting was terrible and it made the stool look black and it wasn't black... XXXXXXX we will know for sure tomorrow as he will be taking a sample to his doctor appt. that it started right after the probiotic gives me hope that is the cause.
Brief Answer:
Follow-up consultaion
Detailed Answer:
You're welcome,
Well, blood is usually seen right after bowel movements and I think that you would notice if blood was present since in cases of bleeding in lower part of bowels, it is bright red.
In case of bleeding in stomach and duodenum, the stool would be black like coffee. Dark brown is not something to be concerned.
There are cases of bleeding which is not seen in stool and this is called occult bleeding. To rule this out he should do red blood count in blood and occult bleed stool test. However, at this point, I don't think this is necessary.
Regards
Follow-up consultaion
Detailed Answer:
You're welcome,
Well, blood is usually seen right after bowel movements and I think that you would notice if blood was present since in cases of bleeding in lower part of bowels, it is bright red.
In case of bleeding in stomach and duodenum, the stool would be black like coffee. Dark brown is not something to be concerned.
There are cases of bleeding which is not seen in stool and this is called occult bleeding. To rule this out he should do red blood count in blood and occult bleed stool test. However, at this point, I don't think this is necessary.
Regards
Above answer was peer-reviewed by :
Dr. Arnab Banerjee
thank you again. he had both of those tests a few months ago and they were fine. red blood count was fine and no blood in the occult test. again, thank you
Brief Answer:
follow-up
Detailed Answer:
Hi,
Well, then you have nothing to worry about
Warm regards
follow-up
Detailed Answer:
Hi,
Well, then you have nothing to worry about
Warm regards
Note: For further follow up on related General & Family Physician Click here.
Above answer was peer-reviewed by :
Dr. Arnab Banerjee
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
