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Fairfax, VA
A 29-year-old male asked:

Im taking doxycycline 100mgx2 a day, and topical clindamycin for acne. its been about a 1 1/2 week since im on it, and little more constipated and stool is more blackish. cause of concern?can antibiotics cause this? on and off. pepto b sometimes?

2 doctor answers2 doctors weighed in
Dr. David Ellis
Family Medicine 44 years experience
Doxycycline is a very broad spectrum antibiotic. This can change the bacterial flora in your colon and also change the color of the stool along with the function of the colon. It is a good idea to take a probiotic daily to help rebalance the bacterial flora in your bowel.
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Dr. Deborah Ungerleider
Pediatrics 38 years experience
Agree with Dr Ellis. Additionally, I don’t recommend PeptoBismol. Please contact your doctor if your stools are pure black or if you see blood.
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Jun 16, 2021

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