Quick answer. Diverticulitis is inflammation or infection of small pouches (diverticula) in the wall of the colon, typically causing pain in the lower left abdomen, fever and a change in bowel habit. Mild cases often settle with antibiotics and rest, but severe pain, high fever or heavy rectal bleeding needs urgent care.
Ongoing tummy pain, reflux or a change in bowel habits?
Message our care team on WhatsApp. Tell us what’s going on and we’ll help you find the right best gastroenterologist — free, with no obligation.
Chat with our care team on WhatsAppNot sure who to see? Find the right specialist →
In a medical emergency, or for severe or sudden symptoms such as breathing difficulty, chest pain, fainting or stroke signs, call 995 immediately.
Diverticulitis happens when small bulging pouches that form in the lining of the large intestine (the colon) become inflamed or infected. It tends to affect adults from middle age onwards, and the pouches themselves (a condition called diverticulosis) are very common with age, often causing no symptoms at all until a flare occurs. In Singapore, where Western-style low-fibre diets have become more common, it is an increasingly recognised cause of lower abdominal pain.
This guide explains what diverticulitis is, how to recognise the symptoms, how a gastroenterologist diagnoses it, and the treatment options available. Most importantly, it sets out the warning signs that mean you should not wait at home and should seek emergency care instead.
At a glance
| Feature | Diverticulosis (pouches only) | Diverticulitis (inflamed/infected) |
|---|---|---|
| Symptoms | Usually none | Pain, fever, unwell |
| Pain | Mild or absent | Persistent, often lower left |
| Fever | No | Often present |
| Bowels | May be normal | Constipation or diarrhoea |
| Action needed | Fibre, monitoring | See a doctor; antibiotics or A&E |
What is diverticulitis?
Diverticula are small pouches that push outward through weak spots in the muscular wall of the colon. Simply having these pouches is called diverticulosis and is extremely common as people get older, often discovered by chance on a colonoscopy or scan. Diverticulitis is what doctors call it when one or more of these pouches becomes inflamed or infected.
It most often affects the sigmoid colon, the S-shaped section on the lower left side, which is why the classic symptom is pain in the lower left abdomen. It is more common with increasing age, and a long-term low-fibre diet is thought to play a part in why the pouches form in the first place.
Symptoms & signs
The hallmark of diverticulitis is abdominal pain that builds up and persists over hours to days, usually on the lower left side. Common symptoms include:
- Persistent pain in the lower left abdomen (sometimes lower right)
- Fever and feeling generally unwell
- A change in bowel habit – constipation or diarrhoea
- Nausea, and sometimes vomiting
- Bloating and tenderness when the tummy is pressed
- Occasionally blood in the stool
Symptoms can range from mild grumbling discomfort to severe pain that stops you in your tracks.
Causes & risk factors
The exact trigger for a flare is not always clear, but inflammation is thought to start when a pouch becomes blocked or its lining is disrupted, allowing bacteria to multiply. Factors that raise the risk include:
- Older age
- A low-fibre, high-processed-food diet
- Being overweight and physical inactivity
- Smoking
- Some pain medicines, such as regular NSAIDs (for example ibuprofen)
- A previous episode of diverticulitis
A higher-fibre diet with plenty of fluids is generally recommended to keep the bowel healthy and may reduce the chance of future episodes.
How it's diagnosed
A doctor will ask about your symptoms and examine your abdomen for tenderness. Because the pain can mimic other conditions, tests are usually needed to confirm diverticulitis and to check for complications:
- CT scan of the abdomen – the main test, which shows inflamed pouches and any abscess, perforation or obstruction
- Blood tests – to look for signs of infection and inflammation
- Urine and stool tests – to rule out other causes
A colonoscopy is usually avoided during an acute flare but may be arranged a few weeks later, once the inflammation has settled, to inspect the bowel and exclude other problems.
Treatment options
Treatment depends on how severe the episode is and whether there are complications.
- Mild, uncomplicated cases – often managed at home with rest, fluids, a temporarily lighter or low-fibre diet, and a course of antibiotics if the doctor judges it necessary.
- More severe cases – may need admission to hospital for intravenous antibiotics, fluids and bowel rest.
- Complicated diverticulitis – an abscess may need drainage, and a perforation, blockage or repeated severe attacks may need surgery to remove the affected segment of colon.
After recovery, a gradual return to a high-fibre diet with good hydration is usually advised to lower the risk of further episodes. Any prices for scans or surgery vary by hospital and setting, so ask your provider for a written estimate.
When to see a doctor & which specialist
See a doctor if you have persistent lower abdominal pain with fever or a marked change in your bowel habit, so the cause can be confirmed and treated. Seek emergency care or call 995 if you have severe, worsening abdominal pain, a high fever, repeated vomiting, a rigid tender abdomen, or heavy rectal bleeding – these can signal a serious complication such as an abscess or perforation that needs urgent treatment.
For diagnosis, ongoing management and to plan a follow-up colonoscopy, the relevant specialist is a gastroenterologist. You can find one through our directory of best gastroenterologists in Singapore.
Self-care and preventing future episodes
Once an acute episode has settled, the focus shifts to keeping the bowel healthy and lowering the chance of another flare. A gradual return to a high-fibre diet, with plenty of fruit, vegetables, wholegrains and fluids, is usually advised. Building fibre up slowly helps avoid bloating. Regular physical activity, maintaining a healthy weight and not smoking are all helpful. There is no longer good evidence that you must avoid nuts, seeds or popcorn, so these can usually be eaten as part of a balanced diet unless your own doctor advises otherwise. If you regularly use anti-inflammatory painkillers such as ibuprofen, ask your doctor whether an alternative is suitable.
Questions to ask your doctor
- Do I need a follow-up colonoscopy, and when?
- How should I build up fibre in my diet safely?
- What symptoms mean I should return urgently?
- Am I likely to have further episodes?
Common questions
Does every episode need antibiotics?
Not always. Many mild, uncomplicated cases settle with rest, fluids and diet changes; your doctor decides whether antibiotics are needed based on your symptoms.
Can MediSave help with scans or surgery?
MediSave can be used for eligible day-surgery procedures and hospital admissions within set limits, and MediShield Life helps cover large hospital bills for Singapore Citizens and Permanent Residents. Ask your provider for a written estimate.
Related guides
- Best Gastroenterology Clinics in Singapore — our editorial shortlist
- gastroenterology clinics directory
- Pancreatitis
- Crohn's disease
- Ulcerative colitis
- Coeliac disease
- Keratosis pilaris
Sources
- NHS – Diverticular disease and diverticulitis
- Mayo Clinic – Diverticulitis
- HealthHub Singapore
- SingHealth – Conditions & Treatments
Part of our Digestive, liver & gut guides · Browse all health topics