Hi Rabbi, Do I need to fast on Taanis Ester if I’m taking antibiotics for a UTI. Thanks

On the minor fast days, one who is unwell is exempt from fasting (משנה ברורה סי’ תקנ ס”ק ד, ילקוט יוסף מועדים עמוד תקלא). Unwell means that a person is feeling sick enough that it prevents them from going about their normal daily routine. On Taanis Esther, since the fast was originally not established specifically for the 14th of Adar, there are some who say it is proper to fast at a later date to make up the missed fast (רמ”א יו”ד סי’ תרפו סעיף ב). Most Poskim, however, rule that one does not need to make up the fast (יחוה דעת חלק א סימן לה, כף החיים סי’ תרפו סעיף כב).

One would be advised to talk to their doctor about fasting with a UTI, and should not fast if the doctor recommends against fasting.

All the best