What is Irritable Bowel Syndrome (IBS)?

Irritable bowel syndrome (IBS) is the most common condition to affect the bowel. It is the bowel function that is abnormal as there is no structural abnormality. There have been a variety of names including spastic constipation, chronic irritable bowel syndrome, spastic colon, spastic colitis and mucous colitis. There is a spectrum of severity ranging from very minimal symptoms to distressing discomfort and pain. IBS may last a few years then disappear by itself.

When food is swallowed, it passes down to the stomach. Here it becomes a fluid that passes through to the small intestine where most of the nutrients are absorbed. The remaining waste products are collected in the colon and rectum, which is emptied during defaecation.

The intestine is a smooth muscle tube with a special inner lining facilitating nutrient absorption. The normal bowel propels its contents along by orderly, smooth-muscle contraction waves called peristalsis. When peristalsis is irregular, the patient may experience discomfort or pain, intermittent diarrhoea and constipation, bloating and flatulence (wind) and these are the typical symptoms of IBS.

How can we diagnose IBS?

Until the last few years, the diagnosis of irritable bowel syndrome was made only after full and extensive investigations showing no structural abnormality. Nowadays, full investigations are only required if there is doubt about the diagnosis from the clinical presentation. Typically, there must be more than three months of recurring or continuous abdominal pain or discomfort that is usually relieved after a bowel action (defaecation). The pain may be mild and infrequent or so severe that there is accompanying sweating or faintness. No single symptom is unique to IBS. There may be a change in Frequency of bowel action or change in stool consistency. Abdominal bloating or distension and passing mucus on the stool are also common.

All of the symptoms of IBS can occur with other bowel diseases and disorders and it is, therefore, important that the diagnosis should be made by a doctor. Examples of chronic bowel inflammatory diseases that could cause pain include Crohn's disease, ulcerative colitis and diverticulitis. Tumours of the bowel become more common as we get older so that an important consideration in deciding how far to investigate the symptoms is your age.

How prevalent is irritable bowel syndrome?

Surveys indicate that at any one time 15% of the adult population are affected by IBS. It is an intermittent disorder and most people are affected by it at some time in their lives. Although 15% of the population will have had symptoms bad enough to require consultation, the majority of those with IBS never consult their doctor. Women report symptoms twice as often as men. Symptoms may start from the age of fifteen although the diagnosis is most frequently made between the ages of 30 and 40. The disorder can occur in childhood and in older age groups. IBS seems to be the most common disorder encountered by gastrointestinal specialists. Over the age of 40 45 years there is an increased chance that symptoms compatible with IBS may be due to other and more serious diseases of the bowel and more active investigation is usually required.

What causes irritable bowel syndrome?

IBS is considered to be a functional disorder. A functional disorder has no known anatomical (structural) or physiological (the way organs work) cause. It seems that there is a disorder of bowel motility. At times, this activity is increased leading to diarrhoea and at other times it is reduced leading to constipation. Some patients trace the origin of their problem to an episode of gastroenteritis (sickness and diarrhoea / food poisoning). The bowel is sensitive to emotional states including anger and anxiety.

What is the pain associated with irritable bowel syndrome like?

The pain seems to be associated partly with the intermittent increased bowel activity (peristalsis) and at other times with constipation. The pain with the peristalsis is colicky - it comes and goes in waves. It may be felt anywhere in the abdomen. There may also be a more constant pain associated with distension of the lowest part of the colon, which is in the left lower quadrant of the abdomen, just before the faeces enter the rectum. There may be pain in the right lower quadrant where the contents from the small intestine enter the large intestine (caecum).

Sometimes there may be associated headaches or migraine. One variety of IBS is called abdominal migraine. Fatigue is a frequent problem in IBS sufferers.

Can irritable bowel syndrome be mistaken for gynaecological problems?

A study in South Manchester in 1989 found that 52% of women presenting to a gynaecological clinic with pelvic pain had symptoms suggestive of irritable bowel syndrome. Only 8% of those with symptoms suggestive of IBS had a proven gynaecological disorder. One cause of pain associated with intercourse (dyspareunia) is IBS.

There may be a relationship between hysterectomy and IBS. A study in Sheffield found that 22% of women had symptoms of IBS before surgery (this is no different from the general population). Following hysterectomy (hysterectomy), 60% of those with IBS symptoms had improved or were symptom free.

The bowel is sensitive to progesterone, which is secreted from the ovary after egg release during the second half of the menstrual cycle (luteal phase - Q 2.13). Progesterone levels increase in pregnancy and this plays a part in the sluggishness of the bowel. Many women are aware of a change in bowel habit during the second half of the menstrual cycle or during their periods. Some studies, but not all, confirm that during the luteal phase the transit time for food to pass through the bowel increases leading to abdominal distension and constipation.


A 45 year old secretary was referred for treatment of pelvic pain before her periods. At laparoscopy the pelvic organs appeared perfectly healthy. It became apparent that her bowels became sluggish before her periods. Regulan ( 40) was commenced before her periods and her pain improved quickly.

A nineteen year old young lady was referred to me for a third opinion and for hysterectomy! She had chronic pelvic pain which was very severe around the time of her periods. When I saw her on the first occasion she was accompanied by her family who stressed the devastating pain that she was experiencing and that the only humane option was for me to remove her womb.

At the age of seventeen she had a laparoscopy and was found to have spots of endometriosis. The endometriosis had been treated by laser, danazol and the pill and she had also received antibiotics. None of these treatments had any effect on her pain. When we reviewed the story, it became apparent that she was having increased Frequency of bowel actions at the time of her periods and she had pain on opening her bowel.

Whilst we felt every sympathy for this young lady’s pain, we felt that other avenues to hysterectomy should be pursued. Colpermin and Regulan were prescribed to be taken as required and particularly from a few days before menstruation and continued through the period. When she attended for her first review, the problem had resolved. Clearly the pain had been from her bowel which is sensitive to the hormone changes that occur around the time of menstruation.

Related Medical Abstracts - Click on the paper title:-

What treatments are available for irritable bowel syndrome?

Firstly, the diagnosis may provide reassurance that there is no other serious problem. There is no single treatment that will cure all symptoms or all patients. Treatment will depend on your symptoms. Correction of a poor quality diet may resolve IBS particularly when the diet is lacking in fibre. Excess caffeine and alcohol should be removed from your diet. You may be aware that certain foods exacerbate your symptoms and these should be avoided.

Codeine phosphate is a moderately strong painkiller that has a role in the management of diarrhoea. It may have a place occasionally when diarrhoea predominates in IBS.

Anti-spasmodic agents reduce the smooth muscle activity of the bowel; they are usually taken before meals. Mebeverine (Colofac MR Solvay) one tablet three times daily, and peppermint oil (Colpermin Pharmacia and Upjohn) one or two capsules three times daily are well tried preparations. Kolanticon (Peckforton) has the antispasmodic dicyclomine in combination with the antacid, aluminium hydroxide, and dimethicone, an antiflatulent; 2 to 4 teaspoonfuls four hourly is the recommended dose.

The effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome has been reviewed in a meta-analysis undertaken in Canada.0801 Randomised controlled trials comparing fibre, antispasmodics, and peppermint oil with placebo or no treatment in adults with irritable bowel syndrome were eligible for inclusion. The minimum duration of therapy considered was one week, and studies had to report either a global assessment of cure or improvement in symptoms, or cure of or improvement in abdominal pain, after treatment. Fibre, antispasmodics, and peppermint oil were all more effective than placebo in the treatment of irritable bowel syndrome.

There have been suggestions that Candida (thrush) may be a factor in IBS. Scientific studies, however, have not shown any consistent relationship between Candida and IBS so that dietary measures to reduce Candida seem to be without foundation.

Related Medical Abstracts - Click on the paper title:-

What other treatments are available for IBS?

Certain foods may appear to trigger IBS symptoms; it may be worthwhile excluding individual foods on a trial basis to see if this helps. Some find that they are particularly sensitive to caffeine and sorbitol and symptoms abate when these are withdrawn from the diet. Some people have lactose intolerance; lactose is found in milk and other dairy products. Others may be intolerant of gluten, which is found in wheat, rye, barely and oats. If there is a suspicion that there may be a food intolerance, the suspected item can be removed from the diet for about ten days. A doctor or dietician should be consulted to ensure that appropriate measures are undertaken.

Between 40% and 60% of patients suffering from IBS have psychological disturbance. A change in lifestyle with reduction of stress may prove beneficial. Stress management is worthy of consideration there are many books on this subject. Hypnotherapy and psychotherapy may have a place. In some circumstances agents such as antidepressants may be considered. The tricyclic antidepressant imipramine reduces bowel activity and may be helpful when diarrhoea is the significant problem. The serotonin reuptake inhibitors (Q 25.5) increase bowel muscle activity and may be preferable if constipation is a feature.

IBS Support Groups

Members of a support group, provide each other with various types of help and information for a particular shared difficulty.

The support may take the form of providing relevant information,

  • relating personal experiences,
  • listening to others' experiences,
  • providing sympathetic understanding and
  • establishing social networks.

A support group may also provide ancillary support, such as serving as a voice for the public or engaging in advocacy.

Support groups maintain interpersonal contact among their members in a variety of ways.

Support groups also maintain contact through printed information rich newsletters, telephone chains, internet forums, and mailing lists.

Support groups offer companionship and information for people coping with diseases or disabilities. Support groups may not be appropriate for everyone, and some find that a support group actually adds to their stress rather than relieving it.

Evaluation of the quality of Web sites is discussed in (Q4.27). You may find that several general women's health sites may help you (internet information). The following are more specialised relevant Web sites:-


IBS Support Groups:


Please click on the required question.