Thank you for the query.
can be caused by Pepto-Bismol
and this is quite common side effect. However in some cases, black stools are also caused by stomach bleeding. It also gives diarrhea
if the bleeding is intensive. The heart rate
increases and you become weaker. So if you have noticed any of such symptoms, you should visit your doctor. Otherwise, you can assume that this is a side effect of Pepto-Bismol.
Amoxycyline and Doxycycline can be taken together, however there is no such antibiotic in the Helicobact Pylori eradication guidelines. Usually such eradication should be started with Amoxiciline 1000 mg twice a day and Metronidazole
500 mg twice a day.
You should not stop this medicines immediately, you should rather consult your doctor.
Hope this will help.