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 answers • 2 doctors weighed in

Dr. David Ellisanswered
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.
Created for people with ongoing healthcare needs but benefits everyone.
Answered Jun 16, 2021

Dr. Deborah Ungerleideranswered
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.
Answered Jun 16, 2021
Last updated Jun 16, 2021
People also asked
Connect with a U.S. board-certified doctor by text or video anytime, anywhere.
24/7 visits - just $44!
50% off with $19/month membership
Disclaimer:
Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.