can certain types of GI 'flu or a case of salmonella be mistaken for a diverticulitis flare up?

A year ago, I was hospitalized and told I had diverticulitis although neither of the MRI's nor the colonoscopy that followed two months later were conclusive.  I was given IV antibiotics and put on a liquid then low residue diet.  Almost a year later I had exactly the same symptoms but to a much lesser degree and here's my real question....my Husband suffered EXACTLY the same symtoms a day or two later.  It took a few days before we were pain free, but were both left feeling tired, lethargic, headachey. etc.  Last week, again I began with the horrible pain at the very bottom of the pelvis (same pain as always), I was exhausted and upset, so I went to the doctor.  Her knee-jerk reaction was, again, diverticulitis and antibiotics.  Again, two days later my Husband presented the same symptoms.  Then the pain moved from the middle of the pelvis to the right for both me and my Husband and we both still had the headache.  Now, a week after the onset of symptoms, my husband who has been on a normal diet feels 100% better, and I, who was on the liquid diet for 3 days and now low residue diet, still have discomfort in the lower right.  I'm thinking this is perhaps not diverticulitis.  How can I know for sure?