Hello and welcome to e health forum.
The diarrhea is most probably due to intake of the broad spectrum antibiotic, Azithromycin.
This will be short lived, and will resolve itself in a few days.
This can be stopped by either stopping the medication, and changing the antibiotic. In addition, taking probiotic supplements with lactobacilli, will help in improving the condition.
You may hence consult your doctor, who can change your antibiotic and advice accordingly.