Is rifaximin safe? And is it safe?

My doctor has prescribed me with rifaximin 550 for 7 days twice a day, I was having abdominal mild pain, nausea and yellow mushy stool(not diarrhoea though). I have read that it does help but result in antibiotic relapse later due to which we have to take it again? Is it safe? Today I observed i had yellow mushy stool and it was with mucus.. should I take rifaximin or wait for it to heal itself. I am having this condition since a month, it started after a course of augmentin, before that nothing was there, m losing weight too. Symptoms right now: At night sometimes i get acid reflux. Yellow mushy stool(with mucus sometimes) Feeling nauseous when empty stomach Please guide me. I am more sceptical because i read it's given for diarrhoea but I don't have diarrhoea rather mushy stool.. and is it safe? I mean about that relapsing part, please guide me