Now having read the rest of your question, having symptoms due to localized
yeast infections is a common problem in people who have taken broad spectrum antibiotics,
and the tetracycline group (doxycycline and others) are among the most common offenders. And azithromycin could do it as well. Localized irritation/rash is the most common symptom, typically involving the anus, vaginal area in women, or the mouth. But some cases may cause transient diarrhea.