 [ Symptoms ] blood in stool last night i had a bit to drink i do not drink very often later in the night i vomited and had diarrhea this morning i have felt like i have had to go to the bathroom a couple time and there was bright blood that came out i can not tell if theres even any feces in there or if its just blood is this linked to drinking and getting sick should i see a doctor [ Disease ] your best bet for a good answer to this question is to consult your pharmacist that said we usually tell women taking oral birth control pills to use secondary birth control such as a condom when taking any antibiotic such as bactrim because some antibiotics may reduce the effectiveness of birth control pills bottom line if you do not know for sure if a particular drug is interfering with your birth control pills always use a back up solution hope this helps