Home Conditions Irritable bowel syndrome (IBS)
Condition · Intestine and colon
Irritable bowel syndrome (IBS)
Irritable bowel syndrome is a common condition in which the gut and the brain do not communicate smoothly. It causes abdominal pain linked to bowel movements, with diarrhoea, constipation or both, while tests are normal. It is a real, treatable condition, and it does not damage the bowel.
At a glance
What it is
A disorder of gut-brain interaction: a sensitive, irregular bowel without inflammation.
Common signs
Abdominal pain related to passing stool, bloating, and loose stools, constipation or both.
How it is confirmed
From the pattern of symptoms, with a few tests to rule out other conditions.
How it is treated
Diet changes, medicines matched to your symptoms, and therapies that calm the gut-brain connection.
What are the signs of IBS?
The usual signs
- Abdominal pain or cramps at least once a week, for months
- Pain that changes with passing stool
- Stools that have become looser, harder or both
- Bloating that builds through the day
- Urgency, or a feeling of incomplete emptying
- Mucus in the stool
The three patterns
- IBS with diarrhoea: mostly loose, frequent stools
- IBS with constipation: mostly hard, infrequent stools
- Mixed IBS: both, in alternation
These are not signs of IBS
See a doctor promptly if you have:
- Blood in the stool
- Weight loss you cannot explain
- Fever, or symptoms that wake you from sleep
- A low blood count
- Symptoms that began after the age of 50
- A close relative with bowel cancer, colitis or coeliac disease
What it is
What is happening inside?
The gut has its own nervous system, which is in constant conversation with the brain. In IBS this system becomes over-sensitive. Normal amounts of gas and stretching are felt as pain, and the bowel moves too quickly, too slowly or irregularly.
Several things can set this off or keep it going: a past gut infection, changes in gut bacteria, foods that ferment easily, and stress or poor sleep. None of them means the symptoms are imagined. IBS is the commonest of the gut-brain axis disorders.
Why it happens
The causes I look for
Several conditions look like IBS or sit alongside it. Finding them changes the treatment.
Small intestinal bacterial overgrowth
Excess bacteria in the small intestine cause gas, bloating and loose stools. See SIBO.
Food intolerances
Lactose and fructose are the commonest. See lactose intolerance.
Coeliac disease
A reaction to gluten that damages the small intestine. A blood test screens for it.
Infections and parasites
Giardia and other gut infections are common in India and are checked in the stool.
Medicines and thyroid
Some diabetes tablets, acid-blockers, antibiotics and supplements upset the bowel, as does an overactive or underactive thyroid.
Pelvic floor problems
In long-standing constipation, the muscles that should relax during a bowel movement tighten instead.
How I find out
Which test answers which question?
IBS is diagnosed from its pattern. Tests are few and chosen to exclude other conditions.
Blood and stool tests
It tells us: Whether there is anaemia, inflammation, coeliac disease, a thyroid problem or a gut infection.
When I use it: At the first visit, especially in IBS with diarrhoea.
Hydrogen breath test
It tells us: Whether bacterial overgrowth or sugar intolerance is contributing.
When I use it: With marked bloating, gas and loose stools.
Colonoscopy
It tells us: That the bowel lining is healthy.
When I use it: Only with warning signs, or when screening is due for your age.
Anorectal manometry
It tells us: Whether the pelvic floor muscles coordinate properly.
When I use it: In constipation that does not respond to treatment.
Treatment
How is IBS treated?
Food
- Regular meals, eaten without hurry
- Soluble fibre such as isabgol (psyllium), started low and increased slowly
- Less caffeine, alcohol, fizzy drinks and very fatty food
- A low FODMAP diet for a limited period, guided by a dietitian, followed by step-by-step reintroduction
See the low FODMAP diet and an Indian IBS diet chart.
Medicines matched to the symptom
- For cramps: antispasmodics and peppermint oil
- For constipation: laxatives and medicines that draw fluid into the bowel
- For diarrhoea: medicines that slow the bowel, and a specific gut antibiotic for selected patients
- For pain that persists: low doses of medicines that calm the gut’s nerves
The gut-brain connection
Gut-directed psychological therapies are recommended in international guidelines for IBS. Cognitive behavioural therapy and gut-directed hypnotherapy for IBS are available through my centre, alongside breathing practice, HRV biofeedback, yoga therapy and sleep correction, taught by a trained team. See gut-directed hypnotherapy and CBT and nervous-system retraining for IBS.
Is surgery ever needed?
No. IBS is never treated with an operation. Part of my role as a surgeon is to protect you from one you do not need.
Root-cause care
The integrative view: what else I look at
Functional medicine approaches IBS as a sequence. Each step prepares the ground for the next:
- Remove what irritates the gut: trigger foods, an infection or bacterial overgrowth when tests show them.
- Replace what digestion lacks, starting with how and when you eat.
- Restore a healthy mix of gut bacteria with fibre and fermented foods that suit you.
- Repair the gut lining with adequate protein and the nutrients you are short of.
- Rebalance sleep, stress and movement, which set the tone of the gut’s nerves.
The Gut Health Program follows this sequence.
Recovery
What should I expect?
| When | What happens |
|---|---|
| First visit | A full history, a limited set of tests, and a clear explanation of the diagnosis. |
| Weeks 2 to 8 | Diet changes and the first medicines. Most people notice fewer bad days. |
| Months 2 to 3 | Foods are reintroduced and the plan is adjusted to what you have learned about your gut. |
| Long term | IBS can flare with infections, travel or stress. You will know what to do when it does. |
Questions patients ask me about IBS
Is IBS all in my head?
No. It is a disorder of how the gut and brain signal to each other, with measurable changes in gut sensitivity and movement. Stress can worsen it, as it worsens many physical conditions.
Can IBS turn into cancer or colitis?
No. IBS does not damage the bowel and does not raise the risk of cancer or inflammatory bowel disease.
Do I need a colonoscopy?
Not usually. It is advised when there are warning signs such as bleeding, weight loss or anaemia, or when you are due for screening.
Does the low FODMAP diet work with Indian food?
Yes, with guidance. Many Indian staples such as rice, some dals in small portions, and several vegetables fit. Wheat, onion, garlic and some pulses are the usual adjustments, and most are reintroduced later.
Does IBS ever go away?
In many people it settles for long periods, and some stop having symptoms. For others it returns from time to time. The aim of treatment is good control and the confidence to manage a flare.
Is IBS linked to anxiety?
Often. About four in ten people with IBS have symptoms of anxiety, and each condition can worsen the other. Treating both gives better results.
What is the difference between IBS and IBD?
IBS is a disorder of gut function with normal tests. IBD means Crohn’s disease and ulcerative colitis, in which the bowel is inflamed.
Should I take probiotics?
The evidence is mixed and depends on the product. A trial for about four weeks is reasonable; if it does not help, stop. See what probiotics are.
Sources
This page is written for patients and is based on the guidelines and studies below. It is for education and does not replace a consultation.
- American College of Gastroenterology guideline on irritable bowel syndrome. Lacy BE et al. Am J Gastroenterol. 2021. doi:10.14309/ajg.0000000000001036
- Rome IV criteria for bowel disorders. Lacy BE et al. Gastroenterology. 2016. PubMed 27144627
- Indian consensus statements on irritable bowel syndrome in adults. Ghoshal UC et al. Indian J Gastroenterol. 2023. PubMed 36961659
- British Society of Gastroenterology guideline on irritable bowel syndrome. Vasant DH et al. Gut. 2021. PubMed 33903147
- Controlled trial of a low FODMAP diet in irritable bowel syndrome. Halmos EP et al. Gastroenterology. 2014. PubMed 24076059
- Meta-analysis of anxiety and depression in irritable bowel syndrome. Zamani M et al. Aliment Pharmacol Ther. 2019. PubMed 31157418