Are you sure it was diverticulitis you were diagnosed with, and not diverticulosis?
Diverticulosis is the formation of pockets in the walls of the lower GI tract. It can be aggravated by straining during constipation as well as by any foods that could 'scratch' the sensitive walls of those outpocketings (diverticulae). It's often diagnosed by CT scan and not uncommon in middle-aged Americans.
Diverticulitis is an infection of the diverticulae and requires immediate attention. Usually the first thing that's tried is antibiotics, often two in combination. When I had it, I was on Cipro and Flagyl together for a month at a time.
Of people who get diverticulitis, about 75-80% won't get it again; their condition can be managed by being careful with the diet and making sure to get enough of the right kind of fiber to avoid constipation without irritating the walls. However, 20-25% have it more than once. Having it more than once within a year is an indicator that it will continue to occur throughout your lifetime. The risk is that, with each infection, the walls tend to get thinner; eventually the bowel can perforate, resulting in a life-threatening emergency.
I had diverticulitis at 3-4 weeks post hyst and then again 11 months later. The gastroenterologist felt that at my age, the prospect of having it repeatedly was just too risky, so once the infection was cleared by antibiotics the second time, I had surgery to remove the diseased portion of my colon. When the surgeon got in there, he found that MOST of my colon was diseased and had to go. He also noted that, in fact, my colon had perforated already - but I was lucky, because an abscess formed around the perforation, containing the infection. The result was a mass of dead tissue and adhesions, all of which also had to be cleaned up.
Hopefully your condition can be managed without surgery. I hope your DR has referred you to a gastroenterologist for follow-up.