Im sorry to hear about your symptoms.
Well diarrhea can occur with diverticulitis and it can persist even after the initiation of antibiotics. It all depends on how long you have been taking the antibiotics. Usually it takes anywhere between 48-96 hours for the antibiotics to kick in and it can take upto two weeks for the diverticulitis to clear up however in some cases it can take a longer period of time. You should see the diarrhea settling within the next 24-48 hours however if it doesnt resolve it is also possible that the diarrhea is occuring as a result of the antibiotics themselves. Diarrhea is a very common side effect of the antibiotics and this wouldnt resolve until the antibiotic was changed or withdrawn. Another possibility is that the diarrhea can be due to a C.Diff infection (this is less likely in the current scenario but is still a possibility). this can occur because teh antibiotics also clear out the good bacteria in the intestine and make you prone to developing this infection. If this is the case then you would have watery diarrhea which may contain blood or mucus. This would need a special antibiotic like metronidazole or vancomycin to be treated.
Now in your case i would stick with the doctors advice and continue with the treatment while keeping yourself hydrated with electrolyte rich fluids or ORS. Drink lots of water. If the diarrhea doesnt improve in the next 24-48 hours or you have worsening of the symptoms like increase in the frequency of the diarrhea, or passage of blood or mucus in the stools. then you would need to call your doctor again or even visit the ER.
I hope I have been helpful and this answers your query. Please remember to assign a feedback rating so JA will compensate me for my time. You are free to ask follow-up questions thereafter at no charge although any bonuses would be appreciated. Please allow up to 24 hours for a follow-up response if I am signed off.
If, for some reason, you are not satisfied with the answer, I would appreciate knowing why so that I can try to clear up any misunderstanding that may have taken place and still earn a positive rating from you. Finally, you may request me in the future by beginning the question with "THIS IS FOR Dr. Muneeb Ali".
Thank you for using Just Answer.