Diverticulitis
Small pouches in the bowel wall (very common after 50) get inflamed. Pain low on the left, fever, bowel changes. Most attacks are mild, settle at home, and don’t need antibiotics.
The diverticulitis ladder
For mild attacks, start at the bottom. Severe pain, vomiting or high fever skips straight to hospital.
- Step 1 · Self-careRest, fluids and paracetamolFor a mild attack: clear fluids or light, low-fibre food for a few days, then back to normal eating.
- Works
- About 19 in 20 mild attacks settle at home: in a trial only 3–6% needed hospital
- Cost
- About $3–10 for paracetamol
- How long
- Usually improving within 2–3 days, better within a week or two
- Watch for
- Avoid ibuprofen-type anti-inflammatories and codeine: linked to complications.
Your bowel wants a quiet weekend, not a burger challenge.
- Step 2 · Self-careFibre, once you’ve recoveredBuild up to 25–30 g a day from veg, fruit, legumes and wholegrains, or add psyllium.
- Works
- High-fibre eaters had about 40% fewer hospital stays for diverticular disease (observational); no good trials on repeat attacks
- Cost
- Groceries; psyllium about $15–35 a tub
- How long
- Build up over 2–4 weeks, then for life
- Watch for
- Wind and bloating if you rush it. Drink more water as fibre goes up.
Nuts, seeds and popcorn are innocent. No need to ban them.
- Step 3 · PrescriptionAntibiotics, only when neededFor people who are unwell, have high fever, a weak immune system or a complication.
- Works
- 3 trials, about 1,300 people: in mild attacks, no fewer complications or operations, and similar recovery, without them
- Cost
- Under the $25 PBS co-payment, about $15–25
- How long
- Usually 5–7 days
- Watch for
- Diarrhoea, nausea, thrush. Tell your doctor about penicillin allergy. No alcohol with metronidazole.
Antibiotics aren’t a reward for turning up. They’re for when they actually help.
- Step 4 · SpecialistHospital treatmentFor severe pain, vomiting or complications such as an abscess: drip fluids and antibiotics, sometimes a drain.
- Works
- About 8 in 10 abscesses next to the bowel settle without surgery; ones further away only about half
- Cost
- Free as a public patient
- How long
- A few days in hospital, then home on tablets
- Watch for
- You’ll usually have a CT scan to check for complications.
If you can’t keep fluids down, home is not the right place.
- Step 5 · ProcedureBowel surgeryRemoving the affected part of the bowel, usually by keyhole surgery.
- Works
- In a trial: better quality of life, and repeat attacks 5% vs 31% at 6 months; serious complications about 1 in 10
- Cost
- Free as a public patient; private costs vary, so get a quote
- How long
- 4–6 weeks recovery
- Watch for
- Major surgery: infection, leaks, sometimes a temporary stoma. Attacks can still recur.
One or two attacks isn’t a reason for surgery on its own.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Mesalazine to prevent attacksLarge trials found it no better than a dummy treatment at preventing further attacks.
- ProbioticsSmall, low-quality studies, and no clear proof they prevent attacks.
- Colon cleanses and “detox” productsNo evidence of benefit, and some irritate the bowel. Fibre is the boring thing that works.
What you can do
- Paracetamol, not anti-inflammatories or codeine, for the pain.
- Drink plenty of water as you increase fibre.
- Stay active, keep a healthy weight and don’t smoke: all linked to fewer attacks.
- After an attack, your doctor may suggest a colonoscopy if you haven’t had one recently.
See your GP if
- Lower tummy pain with fever or a change in bowel habit
- Not improving after 2 to 3 days, or getting worse
- Blood from the bottom or weight loss you can’t explain
Go to the emergency department for severe or worsening tummy pain, a hard, tender tummy, ongoing vomiting, high fever, heavy bleeding, or feeling faint.
Common questions
Do I need antibiotics for diverticulitis?
Not always. Many mild, uncomplicated attacks recover just as well without them if you are otherwise well and complications have been ruled out. Antibiotics are used if you are unwell, have a high fever, a weak immune system or a complication.
What should I eat during a diverticulitis flare?
Clear fluids or a light, low-fibre diet for a few days until the pain eases, then back to normal food. After recovery, build up slowly to 25 to 30 g of fibre a day.
Do I need to avoid nuts and seeds?
No. There’s no evidence nuts, seeds, corn or popcorn cause attacks.
What is the difference between diverticulosis and diverticulitis?
Diverticula are small pouches in the bowel wall that are very common after 50 and usually cause no trouble (diverticulosis). Diverticulitis is when one becomes inflamed.
What does diverticulitis pain feel like?
Usually a steady pain low on the left side of the tummy that builds over a day or so, often with fever, nausea, and constipation or diarrhoea. Severe pain, a rigid tummy, vomiting or high fever needs urgent care.
Can diverticulitis go away on its own?
Mild, uncomplicated diverticulitis often settles in a few days with rest, fluids, a light diet and pain relief, and trials show many people don’t need antibiotics. You should still see a doctor to confirm it and rule out complications.
Will diverticulitis come back?
Roughly 1 in 5 people have another attack within a few years of the first one (more in some studies), and most repeat attacks are mild. Surgery is now rarely needed just because of repeat attacks; it’s considered when attacks are frequent, severe or complicated.
Helpful resources
- Guts UK: Diverticular diseaseUK gut charity’s plain-English guide, myths section and printable leaflet. Free.
- Healthdirect: High-fibre foodsHow much fibre you need and easy ways to get it. Free.
Evidence and more information
- Healthdirect: Diverticular disease
- Cochrane: Antibiotics for uncomplicated diverticulitis
- AAFP: Summary of the Cochrane review
- DINAMO trial: Outpatient care without antibiotics (2021)
- BMJ: Fibre and diverticular disease, EPIC-Oxford (2011)
- Systematic review: Non-surgical care of diverticular abscess (2020)
- JAMA Surgery: LASER trial of elective surgery (2021)
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