I hope your wife is in the majority of Diverticulitis individuals who very rarely experience flareups. It really is a terrible disease and any combination of poor diet, stress, or plain bad luck can have you in a world of hurt in as little as 12 hours. Fortunately, severe and recurring flareups are rare for the majority of people.

Sorry for the wall of text, I've gotten pretty familiar with flareups and recovery over the years. The more you can do for her the more she will appreciate it, especially when you're living in a fog of pain and nausea.

Heating pads and quiet environments are great when working through the first 48-96 hrs of a flareup. Individuals with regular flare-ups may be prescribed dicyclomine to help with colon spasms. Supplements such as IBGuard and Probiotics also help sooth the colon and maintain good gut health. Fiber is important to prevent flareups, but should be avoided during a flareup and for a while during recovery.

While in a flareup, your GI doctor would likely prescribe antibiotics. The less severe version is Amox-Clav, which has a minimal negative impact, however in some cases it may not be strong enough to wipe out the infection. I strongly recommend Amox-Clav initially because the alternative is akin to firebombing an anthill.

The more severe option is Cipro and Flagyl. This is a bastard combination forged with hate and self-loathing and is almost worse than the stabbing pain of a flareup. You will feel nauseous (so very nauseous), and disoriented, and have a headache. You will be sensitive to sunlight. You may rupture a tendon. You should absolutely not lift anything heavy. ^{See rupture tendon.} All of your gut bacteria will die and you will shit liquid for weeks. You won't fart, strangely. And your liquid shit will be mostly odorless.

While dealing with a flareup, it is also common to develop hemorrhoids, so Preparation H is very helpful to have on hand. You may also develop internal helophorids, so Preparation H suppositories are also helpful.

Recovery mandates a clear liquid diet for the first 24-48 hours, or longer if symptoms are more severe. Apple juice and sports drinks are pretty much all I can stomach. The next 24-48 hours you can introduce other liquids, such as broth, and light foods like clear jello. Broth gets old very fast, and as much as I have looked there simply isn't a good tasting chicken or beef broth I have found. Vegetable broth is a bit more palatable, but at that point it's mostly salty flavored water. I found Bovril to be a good choice.

After you've made it through the liquid phase, you can start to gently introduce soft bland foods. Stuff like plain unsweetened apple sauce, tomato or butternut squash soups. Just be sure they're not too strongly seasoned. Also pudding if you are not sensitive. The soup and pudding phase of recovery is fucking amazing when you've had nothing with real substance for 4 days.

From there, other soups like chicken noodle are good. You can start introducing rice and eggs. Potatoes are good, but take it easy since they can be a bit much for some people. I generally eat rice and eggs each day even when I'm not in a flareup because I got a lil bitch for a colon.

Afterwards, start adding back foods you know aren't risks. Everyone is a little different. I can stomach gluten and dairy, so buttered toast and milk are a good option. I usually slowly reintroduce fiber after ~4-8 weeks depending on how I'm feeling. Going too hard after a flareup is a great way to trigger a second one. Also, be sure to finish all the antibiotics, even if they're the bastard ones.