Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Diverticulitis is difficult to treat with antibiotics, if it is severe means chance to develop bleeding and perforation. We can use Amoxicillin clavulinicacid or metronidazole or moxifloxacin or levofloxacin etc. Until examination is done it is difficult to say which stage it is. take low residual diet, use appropriate antibiotics under your doctor guidence. If symptoms not improved please consult your doctor he will examine and treat you accordingly. Hope I have answered your query. Let me know if I can assist you further.