Abdominal pain, CT best diagnostic tool.
Mid to old age.
A third generation cephalosporins PLUS metronidazole is my fav, po therapy or beta lactam allergy would be a quinolone PLUS metronidazole OR tmp/sulfa PLUS metronidazole. Amoxicillin/clavulanate alone should be fine as well.
10 - 14 days total.
If the tic perforates, laproscopic resection has worser (yes, worser) outcomes (PubMed).
And there was one study in England where uncomplicated diverticulitis was treated with observation and they did as well as those with antibiotics(Pubmed. I don't know. I doubt I would have the courage to do this without another study to back it up.