Can One Dose Of 1 Gr Of Zithromax Cause Loose Stools?

hi, i have been prescriped a one does 1 gr of zithromax. both me and my boyfriend due to a vaginal infaction. this was over 1 week ago. but we both have had esxtremely loos stools since that. it's not with the frequency of diahrrea but it is bothering. is this normal and how long will it tke to go away.