Irritable Bowel Syndrome

Causes, Diagnosis And Treatment Of IBS

Irritable bowel syndrome or ibs, is a condition that causes abdominal pain or discomfort, bloating, constipation or diarrhoea and often relieved by opening your bowel. See the top symptoms of ibs, causes, how it is diagnosed and best treatment options available for this condition here.

Irritable bowel syndrome or ibs is caused by abnormal contraction of the muscle in the large intestine due to irritation from disruption in the balance of normal gut sensitivity.Irritable bowel syndrome or ibs is caused by abnormal contraction of the muscle in the large intestine due to irritation from disruption in the balance of normal gut sensitivity.

Christa is a 27-year-old student nurse who also works in a care home for the elderly.

She has been seeing different doctors for the last seven months with complaints of intermittent cramping abdominal pain and bloating.

She "kept going to the toilet frequently than I used to; some days, up to 6 times. I do not always open my bowel, even though I feel I should. When I do, I only pass tiny hard stool or on some occasions, watery diarrhoea. This cramping abdominal pain is ruining my life. I cannot concentrate at work. I feel bloated most of the time. I am not confident to go out with my friends".

Her pain seems to worsen after eating and relieved by passing wind or opening her bowel.  She reports no significant unintended weight loss or change in appetite or any other symptoms.

After undergoing a few test "just to be sure we are not missing out any other causes" her new family physician diagnosed her as having ibs.

She was given some medications as well as dietary advice to help with her symptoms. "For the first time in months, I can now take control of my life again", Christa reports.

Have you been told that you suffer with irritable bowel syndrome?

Millions of people worldwide are well too familiar with the pain and distress that this condition brings upon them.

But what exactly is irritable bowel syndrome (or ibs)? How common is it? What are other conditions that commonly mimic the symptoms of irritable bowel syndrome, with potentially serious consequences if confused for ibs?

What Is Irritable Bowel Syndrome?

Irritable bowel syndrome, known as IBS for short, is a disorder of the gut’s function, causing a number of symptoms like bouts of cramping abdominal pain or discomfort, bloating, diarrhoea or passage of little hard stools (like pellets), which could also alternate with diarrhoea.

It is believed that ibs is caused by abnormal contractions of the muscles of the large intestine due to a disruption in the normal sensitivity of the gut's nervous system.

  • Irritable bowel syndrome shares its signs and symptoms with a number of other serious medical conditions like celiac disease, Crohns disease, ulcerative colitis, endometriosis, bowel cancer and more.

  • It is therefore very important to see your doctor for a proper check up, if you have some or all of the symptoms of irritable bowel syndrome.

  • Though ibs is a physical disease, it does not cause any injury or life-threatening condition. It does not lead to any long term physical damage. No one dies as a result of ibs.

  • Contrary to what some people say, it is not a psychological or psychiatric disease.

  • Irritable bowel syndrome is suffered by about 1 out of every 5 persons. Half of those who suffer with this condition do not seek medical help. 1 out of 3 persons who have this condition are females. It is a disease that affects all ages and races.

  • Many millions of work hours are lost yearly because of this disorder. In severe cases, quality of life can be adversely affected too.

What Causes Irritable Bowel Syndrome?

The exact cause of ibs is unknown.

Bacteria overgrowth has been implicated as a possible contributing factor to ibs.Bacteria overgrowth has been implicated as a possible contributing factor to ibs.

It is increasingly believed that the cause of irritable bowel syndrome might be related to a disruption of the normal balance of good and bad bacteria in the gut.

This leads to bad bacteria overgrowth and production of chemicals that causes irritation to the gut, and thereby disrupting the normal sensitivity of the gut to stress, certain foods and gas.

The exact way this change in the balance of bad gut bacteria and irritation causes IBS is still not fully understood. Nevertheless, there is evidence that many people tend to develop ibs symptoms after:

  • Prolonged use of antibiotics
  • Severe virus infection
  • An attack of gastroenteritis or food poisoning.

It is also believed that ibs may be related to a dysfunctional communication between the gut and the bowel, leading to an overly sensitive gut wall muscle and nerves.

It has been observed that ibs seems to be associated with anxiety disorder.

What Are the Symptoms of IBS?

The symptoms of irritable bowel syndrome include:

  • Abdominal pain or discomfort – on and off for at least six months
  • Bloating – feeling of fullness or gas in the abdomen
  • Passage of small hard stools or watery stools
  • Abdominal pain or discomfort relived by passing stools
  • Passage of mucus in stool

Other symptoms of irritable bowel syndrome could include two or more of any of the above symptoms as well as:

  • Lower back ache
  • Waking up at night to pass urine more than usual
  • Nausea
  • Passing of urine more frequently than usual
  • Feeling tired or lethargic

These symptoms should have been going on for six months or more and certainly present in the last three months. 

In 1992, doctors met in Rome and drew up a tool referred to as the Rome III criteria that helps put together the mix of symptoms to look out for to be able to say to a large extent that someone has ibs.

The Rome Criteria dictates that for you to be diagnosed with ibs, you should have suffered for least three days a month in the past three months, two or more of the following symptoms:

  • Abdominal pain or discomfort that gets better with defecation
  • There must have been a change in the frequency with which you open your bowels
  • There should have been a change in the appearance of your stool – either have become harder (constipation) or loose (diarrhoea)

As you can see from the above, the symptoms of ibs are not specific to this condition alone. It is the combined presence of two or more of the Rome III Criteria as well as any of the other symptoms listed above for about three to six months in a patient that is termed the syndrome (syndrome means a collection of symptoms) of an irritable bowel or ibs.

Alarm Symptoms

Irritable bowel syndrome should not cause any of the following symptoms:

  • Weight loss
  • Blood in stool
  • New onset diarrhoea or constipation in anyone 50 years or more lasting more than six weeks
  • Unexplained anaemia
  • Fever
  • Lump in the abdomen
  • Poor appetite.

If you have been told that you suffer with ibs and you have any of these symptoms, you should see a doctor for some further investigation to exclude more serious causes of symptoms. One or more of these symptoms occurring with any pain or discomfort in the abdomen are referred to as alarm symptoms.

Real Life Case Example of IBS WIth Alarm Symptoms

Julia is a 52-year-old property development consultant.

She has complained of cramping central and lower abdominal pain on and off for over two years.

In the last three months, her pain has worsened to the extent that she is unable to do anything without taking pain killers. She was told that her symptoms are due to irritable bowel syndrome and was given on Nortriptylline and Bentylol.

These medications seemed to help initially but in the last few months their benefit is questionable.

One day, she went to her doctor again with a new complaint of passing blood in her stool.

Julia was re-examined and then sent to have an urgent colonoscopy.

The result came back and revealed wide-spread inflammation of the wall of Julia’s large bowel, with some ulcerations, a condition known as ulcerative colitis.

She was subsequently referred to a gastroenterologist who specialises in ulcerative colitis and placed on treatment.

Julia now lives her life free of the abdominal pain that she has endured everyday for the last two to three years.

It is dangerous to make a diagnosis of irritable bowel syndrome in anyone without first excluding other potentially serious causes of symptoms of ibs.

A detailed analysis of the symptoms complained of, coupled with a physical examination is the minimum that is required to exclude such conditions. In some cases, other tests may be required.

Common conditions that can mimic irritable bowel syndrome include:

  • Lactose intolerance
  • Bile acid diarrhoea
  • Gardiasis
  • Pancreatic insufficiency
  • Crohns Disease
  • Ulcerative colitis
  • Celiac disease
  • Ovarian cancer (in a woman)
  • Bowel or colon cancer
  • Short bowel syndrome.

Diagnosis of IBS

There is no single test or group of tests that can be done to confirm irritable bowel syndrome.

IBS is mainly a diagnosis done, based on the history of symptoms and physical examination. Many times, though, as a precaution, some basic tests would be required to exclude conditions that mimic ibs.

To diagnose someone with irritable bowel syndrome, the patient should have:

  • Abdominal pain or discomfort, bloating and constipation or diarrhoea with any of the other symptoms listed earlier, ongoing for at least six months with no alarm symptoms present.
  • Normal blood test, including Full blood count (CBC), CRP, ESR, Thyroid function test, TTG (celiac disease test) and stool test in some cases (to exclude parasite infection).
  • Abdominal ultrasound scan and CA125 in any woman in whom ovarian cancer is also a possibility.

Extensive testing, colonoscopy (except in the diarrhoea predominant type or if some other diagnosis is suspected) and other invasive testis are not required to make a diagnosis of irritable bowel syndrome.

Types of Irritable Bowel Syndrome

There are four types of ibs based on the predominant symptoms and severity. They are:

  • Diarrhoea Predominant. In these patient, they tend to have abdominal pain and bloating especially after eating and then have bouts of diarrhoea. They may also pass lots of wind with the diarrhoea. It is only then they feel some relief from the pain. Is that you? You would require stool test for giardiasis, celiac disease screening, lactose intolerance and bile acid diarrhoea test (SeHCAT test) and if you are more than 50 years of age, a colonoscopy, to exclude other causes of chronic diarrhoea.
  • Constipation Predominant. These patients tend to have abdominal pain, bloating and pass small hard stools or pellets as their main symptoms. No special testing is required, except colonoscopy, if this is a new symptom in someone 50 years or older.
  • Mixed IBS or Unsub-typed IBS. These patients have abdominal pain, bloating, with alternating periods of constipation or diarrhoea.
  • Pain Dominant IBS. In a small subset of patients, their main symptom is abdominal pain and can have periods of constipation or diarrhoea or both.

Treatment of IBS

Once a diagnosis of ibs is made, treatment should be tailored along a multi-prong approach. This should include:

Dietary and Life Style Change

  • Keep a food diary and identify foods that seems to trigger an attack and eliminate such from your diet.
  • Some patients with constipation dominant ibs report having symptoms with high-fibre food such as wholemeal or whole grain foods. Replace with dissolvable fibre food.
  • If you suffer with the diarrhoea predominant ibs, consider eliminating food high in fructose and lactose. See the FODMAP Diet list and avoid high FODMAP rich foods.
  • Foods rich in refined sugar, artificial sweeteners, sorbitol – rich in chewing gum, and fizzy drinks (soda or pop).
  • Probiotics have been found to be very helpful in many patients in minimizing the symptoms of irritable bowel syndrome. Take a probiotic capsule a day.
  • Taking to time chew and eat could be helpful for some.
  • Drink at least 8 cups of water and other forms of clear fluids like non-caffeinated drinks and herbal teas.
  • Reduce coffee and tea intake to no more than 3 cups per day.
  • Regular exercise and ensuring a good seven to eight-hour sleep every night
  • Good relaxation technique and mindfulness training should be part of a good lifestyle plan.

Use of Medications

The following medications have been found to be helpful for irritable bowel syndrome:

  • Anti-spasm medications like Bentylol, Meberverine, Buscopan especially for those with pain dominant symptoms
  • Nerve calming medications like Nortriptylline, Amitriptyline, or Fluoxetine has been effective in helping with symptoms control in some patients
  • Diarrhoea-stopping medication like Loperamide for those with diarrhoea predominant symptoms
  • Bile acid diarrhoea-stopping medications like Cholesttyramine (sold as Olestyr in some countries) can also be tried in those with diarrhoea not responding to Loperamide or Limotil
  • Antibiotic medications like Rifaximin that stays within the gut and does not get absorbed into the blood to help clear bad bacteria from the gut and restore balance
  • Constipation-stopping medications like Linaclotide (Constella) for those with constipation predominant ibs.

Other Forms of Interventions

These would include:

  • Cognitive Behavioral Therapy (CBT)
  • Biophysical feedback treatment
  • Acupuncture
  • Reflexology.

ICD 9 and ICD 10 Codes for IBS

For insuranec purposes, the ICD 9 or ICD 10 codes for ibs is often requested. They are:

ICD 9 code for irritable bowel syndrome is = 564.1

ICD 10 code for Irritable Bowel Syndrome without diarrhea = K58.9

ICD10 code for ibs with diarrhea = K58.0

ICD 10 code for ibs with constipation = K58.1


  •  Oxford Handbook of General Practice. 4th Edition. By Chantal Simon, Hazel Everitt, Francoise van Dorp, and Matt Burkes.
  • ICD Website -