Thank you for the query.
is most probably caused by antibiotics therapy. For proper intestines function we do have regular intestines bacteria which do protect intestines from pathologic bacteria to grow. When using antibiotics it affects also this good bacteria so the bad onces can grow and cause diarrhea.
Moreover, dark stools (usually black) can be caused by bleeding from stomach or duodenum
It is advisable for you to have full blood work and if low hemoglobin
, upper GI endoscopy
should be performed.
If the bleeding is ruled out, you can start dealing with diarrhea. To do that you should use probiotics and ask your doctor about Rifaximine therapy.
Hope this will help.