Irritable Bowel Syndrome (IBS)


Irritable bowel syndrome (IBS) is a common gut disorder. The cause is not known. Symptoms can be quite variable and include abdominal pain, bloating and sometimes bouts of diarrhea and/or constipation. Symptoms tend to come and go. There is no cure for IBS, but symptoms can often be eased with treatment.

What is IBS and who gets it?

IBS is a common functional disorder of the gut but there is no abnormality in the structure.

IBS can affect anyone at any age, but it commonly first develops in young adults. IBS is slightly more common in women.

What are the symptoms of IBS?

  • Pain and discomfort may occur in different parts of the abdomen. The length and severity of each bout of pain can vary greatly. The pain often eases after passing stool or gas.
  • Bloating and swelling of the abdomen may develop from time to time. One may pass more wind than usual.
  • Changes in stools:
    • Some people have bouts of diarrhea, and some have bouts of constipation.
    • Some people have bouts of diarrhea that alternate with bouts of constipation.
    • Sometimes the stools become pellet-like. At times, mucus may be mixed with the stools.
    • There may have a feeling of not emptying the rectum after going to the toilet.
    • Some people have an urgent need to go to the toilet several times shortly after getting up.
  • Other symptoms which sometimes occur – include: nausea, headache, belching, poor appetite, tiredness, backache, muscle pains, heartburn.

Note: passing blood is not a symptom of IBS and the doctor should be informed about it

What are the tests for IBS?

There is no test that confirms the diagnosis of IBS.

Tests done commonly to exclude other conditions are:

  • Full blood count (FBC)– to rule out lack of iron in the blood (anaemia), which is associated with various gut disorders.
  • Erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) – which can show if there is inflammation in the body (which does not occur with IBS).
  • A blood test for coeliac disease.
  • A stool test to look for a protein called faecal calprotectin. This may be present if you have Crohn’s disease or ulcerative colitis, but is not present in IBS.

More complicated tests such as gastroscopy and colonoscopy are done if symptoms are not typical, or if symptoms develop later in life (over the age of 50) when other conditions need to be ruled out.

What causes IBS?

The cause is not clear. It may have something to do with overactivity of part or parts of the gut. Pain and other symptoms may develop if the contractions become abnormal or overactive.

  • Overactivity of the nerves or muscles of the gut. It is not known why this occurs. Stress or emotional upset may play a role. Symptoms tend to become worse during times of stress or anxiety.
  • Intolerance to certain foods may play a part in some cases.
  • Infection in the gut. IBS is not caused by an ongoing gut infection. However, in some cases, the onset of symptoms seems to follow a bout of a gut infection with diarrhoea and vomiting, called gastroenteritis.
  • Oversensitivity to pain. People with IBS feel more pain when their gut is expanded (dilated) than those without IBS.

What is the treatment IBS?

Many people are reassured that their condition is IBS, and not something more serious such as colitis. Simply understanding about IBS may may ease the severity of symptoms.

No treatment is likely to take away symptoms completely, but treatment can often ease symptoms and improve quality of life.

Lifestyle changes

  • Regular exercise is known to help to ease symptoms.
  • Reduction in stress and other emotional factors may help.
  • Keeping a symptom diary. This may identify triggers, such as a food, alcohol, or emotional stresses, and may show if exercise helps to ease or to prevent symptoms.


General dietary advice for IBS


  • Have regular meals and take time to eat at a leisurely pace.
  • Drink at least eight cups of fluid per day, especially water or other non-caffeinated drinks. This helps to keep the stools (faeces) soft and easy to pass along the gut.
  • Restrict tea and coffee to three cups per day.
  • Restrict the amount of fizzy drinks.
  • Don’t drink too much alcohol.
  • Consider limiting intake of high-fibre food.
  • Limit fresh fruit to three portions per day.
  • If there is diarrhoea, avoid sorbitol, an artificial sweetener found in sugar-free sweets (including chewing gum) and in drinks, and in some diabetic and slimming products.
  • If there is a lot of gas and bloating, consider increasing the intake of oats.


There are two main types of fibre – soluble fibre (which dissolves in water) and insoluble fibre. It is soluble fibre rather than insoluble fibre that seems to help ease symptoms in some cases.

  • Dietary sources of soluble fibre include oats, ispaghula (psyllium), nuts and seeds, some fruit and vegetables and pectins.
  • Insoluble fibre is chiefly found in corn (maize) bran, wheat bran and some fruit and vegetables. In particular, avoid bran as a fibre supplement.

The low-FODMAP diet

Recently, it has been discovered that a low-FODMAP diet may help some people with IBS.

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These are a group of carbohydrates found within foods, which may make IBS symptoms worse.

Examples of foods to avoid in a low-FODMAP diet include:

  • Certain fruits, such as apples, cherries, peaches and nectarines.
  • Some green vegetables, such as peas, cabbage, broccoli and Brussels sprouts.
  • Artificial sweeteners.
  • Foods high in lactose, such as milk, ice cream, cream cheeses, chocolate and sour cream.
  • Individual food intolerance

The foods that are most commonly reported to cause IBS symptoms iare:

  • Wheat.
  • Rye.
  • Barley.
  • Dairy products.
  • Coffee, tea and cola.
  • Onions


Probiotics are nutritional supplements that contain good germs (bacteria). Taking probiotics may increase the good bacteria in the gut which may help to ward off bad bacteria that may have some effect on causing IBS symptoms.


Antispasmodic medicines

These are medicines that relax the muscles in the wall of the gut. There are several types of antispasmodics. For example, mebeverine, hyoscine and peppermint oil.

Note: pain may ease with medication but may not go away completely.

Treating constipation

Constipation is sometimes the main symptom of IBS. If so, it may help to increase dietary fibre. Sometimes laxatives are advised if increasing fibre is not enough. It is best to avoid lactulose in IBS.

New medicines like linaclotide and lubiprostone have been approved for people who have constipation as a main symptom of IBS.

Treating diarrhoea

An antidiarrhoeal medicine may be useful if diarrhoea is a main symptom. Newer drugs like rifaximin and ramosetron are helpful.

Antidepressant medicines

A tricyclic antidepressant is sometimes used to treat IBS. In particular, it tends to work best if pain and diarrhoea are the main symptoms. An example is amitriptyline. Other types of antidepressants, called selective serotonin reuptake inhibitors (SSRIs) eg. Fluoxetine are also occasionally used for IBS.

Psychological treatment

Situations such as family problems, work stress, examinations, recurring thoughts of previous abuse may trigger symptoms of IBS. People with anxious personalities may find symptoms difficult to control.

The relationship between the mind, brain, nervous impulses, and overactivity of internal organs such as the gut is complex. Psychological treatments are mainly considered in people with moderate-to-severe IBS:

What is the outlook?

In most people with IBS, the condition tends to persist long-term. However, the severity of symptoms tends to wax and wane. This is more likely if IBS started after an infection (gastroenteritis).

IBS does not shorten the expected lifespan, it does not lead to cancer of the bowel, and does not cause blockages of the gut, or other serious conditions.

By : Dr. Rajiv Baijal

Designation : Senior Consultant

Department : Gastro

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