CBT in depression
IBS is often perceived as a nuisance rather than a particularly serious disease, but as Dr Peter Whorwell explains, it can be very wearing for patients with recent research suggesting an increased risk of suicidal ideation
It has been estimated that
10-15 per cent of the adult population of Western countries is affected by IBS. Taking the lower of these figures, this leads to about 4.7 million adult sufferers in the UK with 1.2 million attending secondary care and 300,000 being referred to tertiary care.
This tertiary care group represents the really severe patients with this condition and they are as numerous as cases of inflammatory bowel disease.
The total UK Crohn's disease and ulcerative colitis population is in the order of 250,000, emphasising the magnitude of the IBS problem by comparison.
Mental health issues
In secondary care approximately 40-60 per cent of patients with IBS can be shown to have some evidence of psychopathology. However, if non-consulters in the community are identified the prevalence of psychopathology in this group is not particularly excessive despite the fact that their symptoms can be as severe as those of consulters.
This has led to the conclusion that psychopathology affects consultation behaviour rather than necessarily being directly involved in the pathophysiology of IBS.
Anxiety and depression are by far the most common form of psychological problems that occur in patients with IBS, but abnormal illness behaviour and illness attitudes as well as poor coping skills have also been found to be more common than in controls.
The role of sexual and physical abuse is somewhat controversial with some studies, particularly from the US, demonstrating an excess of these particular problems.
However, this is not always the case and we have not found abuse to be especially common in individuals attending our clinics. The identification of chronic, ongoing, social stress in a patient's life is an extremely important issue as it has been shown to make IBS particularly refractory to treatment and some would go as far as saying it results in it being untreatable.
The pathophysiology of IBS is undoubtedly multifactorial and although psychological issues are important, other factors such as disturbances of motility, visceral sensation and central processing as well as genetic and dietary factors also contribute to the problem.
More recently, following the observation that up to 25 per cent of patients date the onset of their IBS to an episode of gastroenteritis, there has been increasing interest in the possibility that there could also be an inflammatory component to the condition.
The severity of illness in IBS patients attending secondary and tertiary care is frequently underestimated. Women with this condition often equate the pain to that of childbirth and the bowel dysfunction can be extreme.
In the diarrhoea predominant category this is often compounded by incapacitating urgency and, not infrequently, episodes of incontinence.
Abdominal distension can also often be very intrusive and sexual function is adversely affected in up to 80 per cent of patients, compared with only 30 per cent in inflammatory bowel disease.
It is now recognised that extra colonic symptoms are common in IBS with the principal complaints being low backache, lethargy, thigh pain, nausea and a range of urological and gynaecological symptoms.
Not only do these add to the burden of illness but they are also important as they often lead to patients being referred to the wrong specialty and frequently undergoing unnecessary investigation and even inappropriate treatment which, on occasions, can be surgical.
Not surprisingly, as a consequence of all these issues, the quality of life of IBS patients is often adversely affected. Using the SF36 generic quality of life instrument, it has been shown that the quality of life of IBS patients attending secondary and tertiary care centres is significantly worse than that of patients with either diabetes or chronic renal disease.
All this leads to a considerable amount of absenteeism with IBS being ranked as second only to the common cold in terms of days lost from work.
IBS patients often feel stigmatised not only because their condition is frequently trivialised but also because they are reluctant to own up to having the disorder for fear of being labelled as psychological cripples.
In addition, potential employers are very wary of these patients because of their perceived psychological status and reputation for a poor sickness record. All this, in conjunction with the notorious inadequacies of treatment leads to a sense of hopelessness on the part of the patient. As a result many individuals have major problems in dealing with the prospect of many years of continuing suffering without any hope of respite and we have experienced some suicides in patients attending our unit, apparently solely due to the burden of their gastroenterological illness.
This prompted us to undertake a survey of suicidal ideation, solely related to their gastrointestinal disorder, in IBS sufferers in the primary, secondary and tertiary care setting, comparing the results with a group of patients with active inflammatory bowel disease.
Our findings are summarised in the box on the right.
The suicide risk
Obviously, the high rate of suicidal ideation we have found in our study does not necessarily mean this will result in the patient actually ending their life.
But we feel strongly that this is a marker of the level of hopelessness and despair experienced by these individuals and clearly indicates that IBS needs to be taken much more seriously by both those who fund and provide health care.
Suicide is well-described in association with chronic disease and in patients suffering from chronic intractable pain. In this situation, hopelessness is a better predictor of suicide than depression and it has been shown that prevention can be facilitated by having someone in whom they can confide.
This may be especially important in IBS where patients are often reluctant or embarrassed to talk about their problem with others. We have evidence that our hypnotherapy service provides this 'counselling' function as well as being of undoubted benefit in treating the symptoms of the disorder.
We routinely audit the activity of the hypnotherapy unit and, in addition to confirming the efficacy of this form of treatment, a surprisingly high number of patients comment that they feel their sense of desperation and hopelessness was relieved, just by having someone to talk to.
What the GP can do
IBS is undoubtedly a challenging disorder to manage, especially as there have been no new medications for the treatment of this condition for more than 20 years. However, it is not impossible to help such patients as long as therapy is individualised.
Many patients are convinced they have some form of dietary allergy, although there is very little evidence to support this notion and therefore allergy testing is not worthwhile. One of the most useful dietary manipulations is to reduce the intake of insoluble fibre such as that contained in brown bread or cereals. This often comes as a great surprise to patients as they have frequently been given the opposite advice.
·Antispasmodics and laxatives
Antispasmodics improve the symptoms of a proportion of patients but often need to be combined with either a laxative or an anti-diarrhoeal, depending on the individual's bowel habit. When prescribing laxatives it is important that they are given on a regular basis and the patient needs to be reassured that there is no evidence that the long-term use of modern laxatives damages the bowel in any way.
Antidepressants of the tricyclic variety are unequivocally beneficial in patients with IBS. It is noteworthy that they are effective at low dose and this lends support to the view that they have a specific effect on IBS rather than mediating their beneficial effect via their antidepressant activity.
Patients should be informed of this fact, as they are much more likely to take this form of medication when they do not feel they are just being fobbed off with an antidepressant.
Tricyclic antidepressants are particularly useful in the diarrhoea-predominant form of IBS but can be used in the presence of constipation, although it may be necessary to co-prescribe a laxative.
The SSRIs do not appear to be so effective in IBS but are worth trying when the tricyclics have failed, or when depression is a more prominent feature of their problem. When all these approaches have been tried with no effect, behavioural techniques such as hypnotherapy or cognitive behaviour therapy are useful, although somewhat limited in their availability.
Cure is not on the agenda, but with careful targeting of symptoms and appropriate use of existing medications, a surprising number of patients can experience a worthwhile improvement in their symptoms.
Our study on suicidal ideation in IBS
ideation in IBS
We found suicidal ideation rates of 4 per cent, 16 per cent and 38 per cent respectively in the primary, secondary and tertiary care groups compared with 15 per cent in the active inflammatory bowel disease subjects (100 patients in each group). Five tertiary care IBS patients had attempted suicide for gastrointestinal reasons compared with only one in the inflammatory bowel disease group.
It might be anticipated that the suicidal ideation identified in our study was related to depression but this was not the case, with mean depression scores not exceeding threshold in any of the groups. Symptom severity, interference with life and inadequacies of treatment were much more important issues in terms of predicting suicidal ideation.
Miller V et al. Clinical Gastroenterology and Hepatology 2004:2: 1064-1068
Peter Whorwell is professor of medicine and gastroenterology, Wythenshawe Hospital, Manchester