Irritable bowel syndrome (IBS) typically causes recurring belly pain or cramps linked to going to the toilet, along with diarrhoea, constipation or a mix of both, and often bloating. You should see a gastroenterologist if symptoms last more than a few weeks, disrupt daily life, start after about age 50, or come with bleeding, weight loss, anaemia or symptoms that wake you at night.
Key takeaways
- IBS is a common, long-term condition of how the gut works, not a disease that damages the bowel or turns into cancer.
- The main symptom is recurring abdominal pain linked to bowel movements, with changes in how often you go or what your stool looks like.
- IBS is grouped by the main bowel pattern: constipation, diarrhoea or mixed.
- Other conditions such as colitis, coeliac disease and bowel cancer can look similar, so warning signs need proper checks.
- A gastroenterologist can confirm the diagnosis, rule out other causes and plan treatment that fits your symptoms.
What is irritable bowel syndrome?
IBS is a disorder of gut-brain interaction. This means the bowel looks normal on tests, but the way the gut moves, senses pain and communicates with the brain is disturbed.
People with IBS often have a more sensitive gut, so normal amounts of gas or stretching can feel painful. Bowel movements may be too fast, causing diarrhoea, or too slow, causing constipation. Stress, poor sleep, certain foods, hormones and a past gut infection can all trigger or worsen symptoms. The link between stress and the gut is covered in our article on how stress affects digestion.
What are the common symptoms of IBS?
The hallmark symptom is abdominal pain or cramping that is related to opening your bowels. The pain may ease after a bowel movement, or come with a change in how often you go or how your stool looks.
Other common symptoms include:
- Bloating or a swollen feeling in the belly, often worse later in the day
- Diarrhoea, constipation, or switching between the two
- A sense of not having fully emptied your bowels
- Urgency, a sudden need to rush to the toilet
- Mucus (a clear or white jelly) in the stool
- Excess wind
Symptoms often come in flare-ups, with good weeks and bad weeks. Many people notice a pattern with meals, stressful periods or their menstrual cycle.
What are the types of IBS?
Doctors group IBS by the main bowel pattern, because treatment differs for each. Knowing your type helps your doctor choose the right approach.
| Type | Main bowel pattern | What you may notice |
|---|---|---|
| IBS-C (constipation) | Hard or lumpy stools most of the time | Straining, infrequent bowel movements, bloating |
| IBS-D (diarrhoea) | Loose or watery stools most of the time | Urgency, frequent trips, cramps before going |
| IBS-M (mixed) | Both hard and loose stools | Alternating between constipation and diarrhoea |
| IBS-U (unclassified) | Does not fit clearly into the above | Pain and bowel changes that vary |
Your type can change over time. Keeping a simple diary of your bowel habits, meals and symptoms for two weeks is useful to bring to your appointment.
How do doctors diagnose IBS?
IBS is diagnosed mainly from your symptom pattern, with tests used to rule out other conditions. Doctors commonly use the Rome IV criteria: abdominal pain on at least one day a week over the past three months, linked to bowel movements or a change in stool frequency or form, with symptoms starting at least six months earlier.
Tests depend on your age, symptoms and risk factors. They may include:
- Blood tests to check for anaemia (low blood count), inflammation and thyroid problems
- Stool tests to check for infection or inflammation in the bowel
- A colonoscopy or gastroscopy, a camera test of the large bowel, if you have warning signs or are due for bowel cancer screening
- Other tests if needed, such as checks for lactose intolerance or coeliac disease
A normal colonoscopy does not mean your symptoms are “all in your head”. It helps confirm IBS by showing there is no inflammation, polyp or other structural cause.
When should you see a gastroenterologist for IBS symptoms?
See a doctor if bowel symptoms last more than a few weeks, keep coming back, or affect your work, sleep or social life. Your GP or a polyclinic can start the assessment, and a gastroenterologist is helpful when the diagnosis is unclear, symptoms do not settle with first-line measures, or warning signs are present.
Arrange a prompt review if you have any of these warning signs, sometimes called red flags:
- Blood in your stool or black, tarry stools
- Unexplained weight loss
- Symptoms that wake you from sleep
- Iron deficiency or anaemia on a blood test
- Fever or ongoing diarrhoea
- New or changed bowel symptoms after about age 50
- A family history of bowel cancer, inflammatory bowel disease or coeliac disease
- A lump in the abdomen or back passage
These signs do not mean you have a serious condition, but they are reasons to look beyond IBS. Our article on signs you should consult a gastroenterologist covers other symptoms worth checking. In Singapore, bowel cancer screening is generally recommended from age 50 for people at average risk, and earlier for those with a strong family history, as described on our colon cancer and polyp page.
How is IBS managed?
IBS is managed rather than cured, and most people can reduce their symptoms a great deal. Treatment is tailored to your main symptoms and triggers.
Common approaches include:
- Regular eating habits: eating at regular times, not skipping meals and eating slowly.
- Diet changes: limiting greasy food, alcohol and caffeine, and for some people a structured low-FODMAP diet, which cuts down on certain fermentable carbohydrates, ideally with a dietitian’s guidance.
- Fibre adjustments: soluble fibre, such as oats or psyllium, often helps more than bran.
- Physical activity and sleep: regular exercise and good sleep help both bowel habits and stress levels.
- Stress management: relaxation techniques, and in some cases gut-directed psychological therapy.
- Medication: chosen for your symptoms, for example to ease cramps, soften stools or slow diarrhoea.
Research into the gut microbiome, the community of bacteria living in the gut, is also helping doctors understand IBS. You can read more on our page on gut microbiome and health.
Frequently Asked Questions
No. IBS does not damage the bowel and does not increase your risk of bowel cancer. However, some bowel cancer symptoms can look like IBS, so new symptoms, especially after about age 50 or with warning signs, should be checked.
No. Inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, causes visible inflammation and damage in the bowel. IBS does not. The two can share symptoms, which is why stool tests or a colonoscopy may be used to tell them apart.
It can for some people. Chilli, rich curries, deep-fried food, alcohol and large meals are common triggers reported by people with IBS in Singapore. Triggers vary, so a food and symptom diary helps you find your own.
IBS tends to be long-term, with symptoms that come and go. Some people have long periods with few symptoms. Treatment aims to reduce flare-ups and help you manage them.
At private clinics, you can generally book a specialist consultation directly. If you plan to use MediSave, insurance or subsidised care at a public hospital, check whether a GP or polyclinic referral is needed first.