As a gut health dietitian service, we see a lot of diverticulitis cases — and honestly, the pattern we see most often is this: someone has a flare, they recover, they change nothing, and a few months later they’re back in the ER. Not because they did anything wrong, but because nobody told them what to actually fix.
I was on a call with a client last month who’d just come out of hospital with her second diverticulitis flare in two years. She said, “Joe, they gave me antibiotics, a leaflet about soft foods, and sent me home. Same as last time. Nobody told me why it keeps happening.” That’s a conversation I have constantly, and it’s exactly why I put this together.
Here are the 5 things you should be doing after a flare, and why most people never get told about them.
Below is a video we made; there is also a written version underneath.
Get the Fiber Right (Not Just More of It)
One of our clients, Narelle, had been eating a textbook high-fiber diet for years and still kept having diverticulitis flares. Nobody could figure it out. She was doing everything the standard advice says — plenty of fiber, careful diet, following the rules. But the flares kept coming.
When she came to us, we didn’t just ask “how much fiber?” We broke it down by type. What we found was that she was loading up on insoluble fiber — the rough kind from wheat bran and raw vegetables — while her gut was still in recovery mode. That was the piece nobody had identified.
Fiber isn’t one thing. It’s a broad category that includes everything from oat bran to raw carrot to wheat bran, and these behave very differently in your gut.
Soluble fiber dissolves in water and forms a gel-like consistency. It slows motility, softens stools, and is generally well tolerated even in a sensitive gut. You’ll find it in oats, cooked vegetables, canned legumes, and ripe bananas.
Insoluble fiber is the opposite. It adds bulk and moves quickly through the bowel. In a healthy gut, that’s fine. But in someone who’s just had a diverticulitis flare and has a damaged, inflamed colon wall, large amounts of insoluble fiber can be hard to tolerate and irritating.
There’s also a FODMAP layer to this — a number of high-fiber foods are also high in FODMAPs, which are known irritants in a sensitive gut. So when you’re adding fiber back in, it helps to prioritize low FODMAP sources as well.
Summary: “Eat more fiber” is the wrong conversation after a flare. The right conversation is which type of fiber, at what dose, and at what stage of recovery — and the answer is different for everyone, which is exactly why generic advice keeps failing people.
Rebuild What Antibiotics Wiped Out
Most diverticulitis flares are treated with antibiotics, and for the right type of diverticulitis, that’s appropriate. But antibiotics do something most people don’t think about: they disrupt the gut microbiome — not just the bad bacteria, but the good ones too.
Research shows that people with diverticular disease already have measurable differences in their gut microbiome compared to those without it — reduced bacterial diversity, lower levels of beneficial bacteria, and changes in the microbial metabolite profile (1). That matters because a healthy, diverse gut microbiome plays a role in maintaining the mucus layer that lines your colon, regulating inflammation, and keeping the gut wall strong.
After a course of antibiotics, you lose a significant portion of that microbial ecosystem. And if you don’t take deliberate steps to rebuild it, you’re operating with a compromised gut environment.
The fix isn’t just “take a probiotic.” A capsule with two or three strains isn’t going to rebuild the diversity you lost. What actually helps is a deliberately varied, plant-heavy diet in the weeks after recovery: fermented foods like natural yoghurt, kefir, or sauerkraut; prebiotic foods like cooked and cooled rice or potato, onion or garlic if tolerated, and leeks; and a reduction in ultra-processed foods, which are consistently associated with lower gut microbiome diversity.
Summary: Antibiotics clear an infection, but they also strip away beneficial bacteria your gut relies on. Rebuilding that ecosystem deliberately — through varied plant foods, fermented foods, prebiotics, and less ultra-processed food — is a step most people skip entirely after finishing treatment.
Stop Shrinking the Food List
After a flare, it’s natural to become cautious about food. You had a painful experience, possibly a hospital stay, and you don’t want it to happen again. So you start cutting foods. Then a few more. Then a few more after that. Within a few months, many people are eating five or six foods and still having symptoms.
This is one of the most common patterns we see, and it rarely leads anywhere useful. When you’ve removed everything, you no longer have any information. You can’t tell what’s actually triggering what. And your relationship with food becomes increasingly fearful, increasingly restricted, and increasingly miserable.
Restriction feels like protection. But what it actually does is remove the data you need to understand your gut, while also reducing the dietary diversity that feeds a healthy microbiome.
The goal after a diverticulitis flare isn’t to find a universal safe list — there isn’t one. The goal is to identify your specific triggers through a structured, guided approach, so you end up with a clear picture of what your gut tolerates, not a shrinking list of things you’re too scared to try.
Summary: Cutting more and more foods after a flare feels protective, but it removes the information you need to actually understand your triggers. A structured, guided approach beats an ever-shrinking “safe” list.
If you’re just getting started, download our low FODMAP Food List Guide to get clarity on common food triggers
Tap the blue button below to download our “Eat This, Not That” list as well as additional resources for Diverticulitis (it’s free!)
Look Beyond the Plate
Diet is important, but diverticulitis isn’t purely a diet condition, and if you treat it like one, you’ll keep missing pieces of the puzzle. A few things most people don’t connect to diverticulitis risk:
NSAIDs. Aspirin, ibuprofen, and naproxen are some of the most commonly used medications in the world, and research consistently links them to a higher risk of diverticulitis. A 2022 meta-analysis of 13 studies found that regular NSAID use was significantly associated with a higher risk of diverticular bleeding and complicated diverticulitis (2). Many people with diverticulitis also have joint pain or headaches and are taking ibuprofen regularly without realizing it’s a factor.
Dehydration. Hard, dry stools require more muscular effort to move through the colon. Think of it like a bicycle tyre — it doesn’t burst anywhere, it bursts at the thin spots. Your colon has thin spots too, where tiny blood vessels pass through the muscular wall. When your colon has to squeeze harder to move dry, compacted stool, that extra effort raises internal pressure — and pressure at those weak points, over time, is part of what pushes tissue through and creates diverticula in the first place. Staying well-hydrated is one of the most direct ways to soften that mechanical load.
Physical activity. Physical inactivity is independently associated with higher diverticular disease risk (3). Movement supports gut motility, reduces the time fecal matter spends in contact with the colon wall, and helps modulate cortisol.
Chronic stress. The gut and brain are in constant communication. Chronic stress affects gut motility, immune function, and the integrity of the gut lining. It’s not the whole story, but it’s part of it — and ignoring it leaves a lever unpulled.
Summary: Diverticulitis risk isn’t just about food. Commonly used medications like NSAIDs, dehydration, physical inactivity, and chronic stress all play a measurable role, and addressing them is part of a complete prevention plan.
Get Specific, Not Generic
This is the one most people skip, and in my opinion, it’s the most important.
Most people leave the hospital after a diverticulitis flare without really understanding what happened. They don’t know if their diverticulitis was classified as complicated or uncomplicated. They don’t know where in the colon the main issue is. They don’t have a clear plan for the months ahead. And they don’t have any testing to understand what their specific gut environment looks like.
So they manage their condition based on generic advice. They search online, find conflicting information, and try to apply blanket recommendations that weren’t designed for their specific situation. When things don’t improve, or another flare happens, they’re left confused.
Here’s the difference we see when someone comes to us with appropriate context about their situation versus someone managing on generic advice alone: the person with context knows what they’re dealing with. They know which interventions make sense for them specifically. They’re not guessing. They’re not cutting foods at random. They have a clear picture, and that picture comes from appropriate testing — whether that’s understanding the microbiome profile, assessing specific dietary triggers in a structured way, understanding vagus nerve sensitivity and nervous system regulation, or reviewing the full picture of diet, lifestyle, medications, and stress to figure out which levers to pull, and in what order.
Summary: Generic advice gets generic results. Understanding your specific diverticulitis classification, triggers, and gut environment through proper testing is what turns guesswork into an actual plan.
What Should Your Next Steps Be?
If you’ve had a diverticulitis flare and were sent home with little more than a leaflet, you’re not alone — and it’s not a sign you’re managing it wrong. It’s a sign the standard approach often stops short of what’s actually needed to prevent a recurrence.
That’s exactly what we built our 4-SURE pathway for. It’s a structured process that identifies whether you have the right eating pattern in place, whether the right tests have been done, and what your actual next step is based on your specific situation.
To learn more about our integrated approach, I invite you to apply for a nutrition assessment call with us. We’ll help you make sense of what’s really happening and map out the next steps to get you feeling confident again — not just temporarily avoiding symptoms, but addressing the root cause and fixing your gut issues for good.
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