Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
Does Clarithromycin Or Metronidazole Cause Dark Stools?
Question: Does clarithromycin or metronidazole cause dark stools. Positive H. Pylori stool dark no blood. On antibiotics starting third day. No stomach pain.
Hi XXXXXXX,
Probably none of them is causing it. I believe you are probably taking Bismuth subsalicylate (Peptobismol) as well, which is commonly given together with these antibiotics in order to treat H. Pylori. Bismuth subsalicylate is very well known to cause dark almost black stools.
Clarithromycin most common side effects include diarrhea, nausea, taste changes or even a rash.
Metronidazole most common side effects include nausea, metallic taste, headaches, diarrhea.
However keep in mind that if the stool is now pasty, tarry, black and foul smelling then this could mean you have digested blood on the stool (from an ulcer or other source of bleeding from the stomach / intestines).
Hope this helps. Let me know if you have other concerns.
Probably none of them is causing it. I believe you are probably taking Bismuth subsalicylate (Peptobismol) as well, which is commonly given together with these antibiotics in order to treat H. Pylori. Bismuth subsalicylate is very well known to cause dark almost black stools.
Clarithromycin most common side effects include diarrhea, nausea, taste changes or even a rash.
Metronidazole most common side effects include nausea, metallic taste, headaches, diarrhea.
However keep in mind that if the stool is now pasty, tarry, black and foul smelling then this could mean you have digested blood on the stool (from an ulcer or other source of bleeding from the stomach / intestines).
Hope this helps. Let me know if you have other concerns.
Note: For further follow up on digestive issues share your reports here and Click here.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
