Diverticulitis, diverticulosis and diverticula disease – what's the difference? By understanding how diverticula disease develops and the role of nutrition in prevention and treatment, you can take proactive steps to support your gut health.
Here’s how diverticulosis develops:
- Straining to go to the toilet, often from constipation, can increase pressure in your large bowel, the colon. Over time, this pressure can cause weak spots in the colon wall to bulge outwards, forming diverticula.
- The presence of diverticula is called diverticulosis, which can cause minor symptoms, such as flatulence or bloating.
- When these diverticula pouches become inflamed or infected, it’s referred to as diverticulitis. Common symptoms of diverticulitis include sharp abdominal pain, fever, cramping, and even blood in stool.
Diverticulitis becomes more common with age. Around 10% of people have diverticulosis by age 40, and about 50% have it by age 80. However, lifestyle factors can significantly affect your risk of developing - no matter your age.
Risk factors you can change to reduce your risk of developing diverticulitis:
- Low fibre intake
- Not drinking enough water
- Physical inactivity
- High alcohol consumption (especially binge drinking or having more than 3 standard drinks in one sitting)
- Smoking
- Low vitamin D levels
- Long-term use of specific medications, including:
- Acid reflux medications
- Some blood pressure medications
- Aspirin
What to Eat During a Flare-Up
While high-fibre foods help prevent diverticulitis, it’s not appropriate during an active flare-up. During this time, your gut needs to rest and recover.
A short-term low-fibre diet (usually 1–4 days) can include:
- White bread, crumpets, English muffins
- Low-fibre cereals (e.g., Rice Bubbles, Corn Flakes)
- White rice, white pasta
- Peeled and well-cooked vegetables (e.g., pumpkin, potato without skin)
- Soft fruits without skins or seeds, tinned fruit
- Adequate fluid intake (water, oral rehydration solutions, clear broths)
Avoid nuts, seeds, legumes, raw vegetables, and wholegrains during this time. Once a flare-up has passed, it’s important to gradually reintroduce fibre and gradually build up to a consistent, high fibre eating pattern.
What to Eat to Support Bowel Health and Protect Against Diverticulosis
The way you eat can either support a healthy gut or increase the risk of issues as you age. A diet low in fibre and high in ultra-processed foods can increase risk of constipation, increase pressure in the colon, and increase the likelihood of diverticula to form.
On the flip side, eating a healthy diet rich in high fibre, whole foods, and drinking plenty of water helps your bowels work the way they’re meant to. Fibre keeps things moving smoothly, lowers pressure in your colon, and fuels the good bugs that keep your gut lining strong, and reduces your risk of inflammation.
Aim for a higher fibre diet containing at least 30g of fibre per day by including:
- Wholegrain and wholemeal bread
- High-fibre cereals (e.g., Weet-Bix, oats, bran-based cereals)
- Brown rice, wholemeal pasta
- Legumes (e.g., lentils, chickpeas, baked beans)
- Vegetables and fruits with skin
- Nuts and seeds
- Fibre supplements if needed (e.g., psyllium husk, oat bran)
- Prunes
Need some high fibre recipe inspo? Check out our favourites with over 10g/serve!
- Lauren's Roast Vegetable Pasta - 17g fibre per serve
- Easy Overnight Oats - 11g fibre per serve
- Black bean quesadilla with speedy guacamole – 13g fibre per serve
- Easy Vegetable & Chickpea Slow Cooker Curry – 17g fibre per serve
- Berry and oat smoothie bowl – 11g fibre per serve
To learn more about managing diverticulitis – listen to Nutrition Science Bites Episode “Diverticulitis - What is it and what to eat to beat or treat it!” with Laureate Professor Clare Collins, and Ilyse Jones here.
If you need personalised support from a dietitian, find one near you here.
