What are the symptoms of irritable bowel syndrome?

The symptoms of irritable bowel syndrome vary from person to person. Some people get constipation, some people get diarrhoea, and some people get both of them but at different times. IBS is diagnosed based on the symptoms - there is no test to confirm IBS but tests can be useful to rule out other conditions.

Common symptoms of IBS are:

• Tummy (abdominal) pain.

• Cramps.

• Bloating.

• Constipation

• Diarrhoea.

If you think you may have IBS find out what to do here. This will tell you if you need to see a doctor and how it is treated.

In this series of articles centred around irritable bowel syndrome you can read about symptoms of IBS, IBS treatment and IBS causes - all written by one of our expert GPs.

The rest of this feature will take an in-depth look at the symptoms of IBS as, at Patient, we know our readers sometimes want to have a deep dive into certain topics.

What are the symptoms of IBS?

Tummy (abdominal) pain

People with IBS experience this common symptom in different ways - the pain might be crampy, sharp, burning, or a feeling of fullness. This is often felt at the bottom of the tummy, below the belly button.

People with IBS often find that the pain is worse after eating, but gets better after having a poo (bowel movement).

Bloating

People with IBS often feel like their tummy or stomach feels uncomfortably full, or swollen- especially after food or at the end of the day.

Diarrhoea and constipation

IBS can cause diarrhoea (watery, loose stools - poo) and constipation (hard, firm poo that's difficult to pass). Some people experience IBS that causes diarrhoea only (IBS with diarrhoea, or IBS-D). Some get constipation only with IBS (IBS with constipation, or IBS-C) and others alternate between the two (IBS with mixed bowel habits, or IBS-M) - this is one way to divide up types of IBS.

Excessive farting (flatulence)

People with IBS might experience excessive farting or flatulence.

Mucus in the poo

It's normal for the gut to produce some mucus, but people with IBS commonly have excess mucus in their gut, which can come out in the poo.

Other poo problems

IBS can cause other difficulties with pooing which sometimes have a big impact on people's quality of life. These include:

• Suddenly feeling the need to use the toilet to poo (faecal urgency) - people might plan their schedule so that they are always near a toilet, which can affect their daily lives.

• Straining when pooing.

• Feeling like the bowel hasn't fully emptied despite pooing (incomplete evacuation).

• Being unable to control the bowels - missing the toilet or having accidents in their underwear (faecal incontinence).

Problems outside the gut

IBS can cause, or commonly be found alongside, a variety of other symptoms, such as:

• Body pain elsewhere - such as back pain.

• Tiredness, fatigue, and exhaustion.

• Headaches and migraines.

• Nausea.

• Bladder problems - such as having to wee frequently and feeling a sudden urgent need to wee (overactive bladder) or needing to wee frequently, with long-lasting bladder discomfort or pain (interstitial cystitis).

• Chronic pelvic pain - in women, pain in the lower stomach or pelvis that is there all or most of the time, for months.

• Anxiety, depression, and stress - the connections between these and IBS are complicated and probably go in both directions. Having distressing symptoms from a long-lasting condition like IBS can negatively affect people's mental health, causing feelings of anxiety and low mood. It's also possible that problems with the way the gut is working, as seen in IBS, might affect the brain more directly. Anxiety and stress are also common triggers for IBS symptoms, and can make symptoms of IBS worse.

Patient picks for Irritable bowel syndrome

Probiotics for IBS: do they work?

Irritable bowel syndrome

What does IBS feel like?

Almost everyone will experience abdominal pain, bloating, and diarrhoea and/or constipation at one time in their life, but people with IBS get them frequently.

IBS often affects peoples daily lives - for example, IBS is a common cause of being off work.

Some people have mild symptoms of IBS that are easily controlled by simple treatments, or simply get better with time. Others with severe IBS have highly distressing symptoms that significantly impact their lives and they might find managing IBS difficult.

IBS is considered a long-term condition and can be lifelong for some people.

Can IBS symptoms come and go?

IBS symptoms usually come and go. People often find that their symptoms flare up for days, weeks or even months, but then get better for a time.

How long does an IBS flare-up last?

This differs from person to person and depends exactly on what is causing the flare-up. For example, if the flare up is caused by something easily identifiable and changeable - such as eating a certain food - then removing that trigger can mean that the flare-up improves within days. For things that are difficult to change, or when it's not clear what is triggering an IBS flare, symptoms may take weeks or months to improve.

When to see a doctor for IBS symptoms

Many of the symptoms of IBS occur in healthy people occasionally, so if you have mild symptoms that get better after a few days as a one-off, you don't necessarily need to speak to a doctor.

There are some symptoms that are potentially concerning, because IBS doesn't usually cause these. Instead, these can sometimes be caused by potentially serious conditions, such as inflammatory bowel disease (IBD), bowel cancer or ovarian cancer.

How to diagnose IBS

Doctors should ask about your symptoms, about the impact they are having on you, and about symptoms that might suggest other, more serious causes - like those listed above. The Rome criteria¹ are a set of symptoms that can be used to diagnose IBS - although for some people, particularly those with milder symptoms, these may not be so useful.

IBS symptoms vary a lot between people, and in cases when symptoms aren't typical, it can be difficult to make the diagnosis of IBS. Initial tests will usually include:

• A full blood count (blood test) to look for anaemia or inflammation.

• A blood test to look for inflammation - C-reactive protein (CRP) or erythrocyte sedimentation ratio (ESR).

• A blood test to look for coeliac disease.

• A poo test (calprotectin) - particularly for younger people with diarrhoea, to look for inflammation in the digestive tract, which might suggest inflammatory bowel disease.

If these tests are normal, your symptoms fit with IBS, and you don't have any other signs or symptoms that suggest another serious condition, your GP can confidently make the diagnosis of IBS, and offer treatment. Further tests generally aren't required in this case.

Additional tests

There are some situations where GPs might suggest other tests, based on specific signs and symptoms. For example:

• A qFIT test - to look for tiny amounts of blood in the poo. This might be done to help rule out bowel cancer. A negative (normal) result makes bowel cancer very unlikely. This is more likely to be done in older people where bowel cancer becomes more common but also if there are any other concerning features, such as a family history of bowel cancer, blood in the poo, or unexplained weight loss.

• Tests for ovarian cancer - particularly in women over the age of 50. This can cause similar symptoms to IBS, and becomes more common with age. This is usually a blood test (CA 125), and sometimes also an ultrasound scan.

• A poo test to look for a bacterial infection in the stomach (Helicobacter pylori) - if there are symptoms suggestive of stomach irritation (gastritis) or heartburn.

Some other tests might be offered by hospital specialists, if there are signs, symptoms, or test results suggestive of another cause. These tests aren't required, or helpful, for most people with IBS, but have a role in some specific situations. These include:

• A colonoscopy - a flexible tube with a camera that looks at the inside of the colon. This looks for inflammatory bowel disease and colon cancer. This is increasingly being done after a positive qFIT test or calprotectin test, but might also be offered if there are other reasons to suspect one of those conditions.

• A SeHCAT scan - to look for bile acid diarrhoea. Might be considered if someone has diarrhoea at night, or has diarrhoea and has had their gallbladder removed (cholecystectomy).

• Anorectal physiology - using a small tube with a balloon to measure the strength of the muscles inside the rectum. This can be useful for people who have problems pooing, or have faecal incontinence, to guide further treatment.

• Hydrogen breath testing - to look for bacterial overgrowth or lactose intolerance, has sometimes been done. However, the British Society for Gastroenterology stated in 2021 that these tests are not helpful or reliable in people with IBS.

Complications of IBS

IBS isn't a life-threatening condition, and doesn't cause other serious conditions, such as bowel cancer.

The main complications of IBS are the effects the symptoms have on people's lives. Some people find that their quality of life is significantly affected by IBS - they might miss work, school, or have difficulty living life in the way they want to. Mental health can suffer, too. People with IBS are more likely to have depression or anxiety.

Further reading

1. Rome IV Criteria; Rome Foundation.

2. Personal Daily Diary (IBS); International Foundation for Gastrointestinal Disorders.

3. Irritable bowel syndrome; NICE CKS, September 2022 (UK access only).

4. Vasant DH, et al; British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021 Jul;70(7):1214-1240. doi: 10.1136/gutjnl-2021-324598. Epub 2021 Apr 26.

5. Rome IV Criteria; Rome Foundation.

6. Personal Daily Diary (IBS); International Foundation for Gastrointestinal Disorders.