Review
Irritable Bowel Syndrome: Toward an Understanding of Severity

https://doi.org/10.1016/S1542-3565(05)00157-6Get rights and content

Irritable bowel syndrome (IBS) is a chronic disorder with symptoms that range in severity from mild and intermittent to severe and continuous. Although severity is a guiding factor in clinical decision making related to diagnosis and treatment, current guidelines related to IBS do not address the issue of severity. Recent data suggest that severity as a multidimensional concept, not fully explained by intensity of symptoms, has important clinical implications including health care utilization and health-related quality of life. Components of IBS severity include symptom intensity, time of assessment, whether the patient or physician makes the severity determination, the type of scale used to measure severity, and the degree of disability or impairment. Currently no consensus definition of IBS severity exists, although 2 validated scales of IBS severity have recently been published. Review of the literature suggests that the prevalence of severe or very severe IBS is higher than previously estimated with a range from 3%–69%. Individual IBS symptoms are important but are not sufficient to explain severity. Rather, severity has multiple components including health-related quality of life, psychosocial factors, health care utilization behaviors, and burden of illness. However, studies have not been adequately designed to determine the relative values of these factors in IBS severity.

Section snippets

Methods

We conducted an English language literature search by using the MEDLINE, PsycLIT, HealthSTAR, Cochrane, and EMBASE databases for the time period 1966 through November 2004. Our search included the heading “colonic diseases functional” as well as combinations of key words such as “severity,” “severe,” and “severity of illness.” In addition, relevant studies were identified through a manual search of the references found online.

Significance of Severity

It is difficult to understand the issue of IBS severity without first understanding the definitions for IBS per se and its historical development. The first diagnostic criteria, published in 1978 by Manning et al,4 identified 6 symptoms (Table 1) that were present more commonly in patients with IBS than in patients with other gastrointestinal diseases. Neither the duration nor the severity of symptoms was evaluated as a potential means of discriminating IBS from other gastrointestinal

Components of Severity in Irritable Bowel Syndrome

Although no consensus on the standard for measuring severity exists, a global assessment of IBS severity (eg, wherein the patient is asked, “Rate the severity of your symptoms”) is an attractive measure. Similar to self-report global measures in clinical trials and QOL assessments, it encompasses one’s experience of a wide range of symptoms and bothersome factors that contribute to the self-perception of severity. This global measure is composed of several components.

Symptom intensity is

Validated Measures of Irritable Bowel Syndrome Severity

There are 2 validated measures of severity, each with its strengths and limitations. The Functional Bowel Disorder Severity Index (FBDSI)26 includes 3 clinical factors that were shown to significantly predict the physician’s rating of severity: (1) patient perception of the intensity of current abdominal pain by using a visual analogue scale, (2) number of physician visits in previous 6 months, and (3) existence of constant or frequently recurrent and disabling pain (Table 3).

The FBDSI has been

Irritable Bowel Syndrome Subtype

A study by Schmulson et al31 found no significant difference in patient-reported severity between patients with constipation- and diarrhea-predominant IBS. However, the study by Coffin et al12 found that IBS severity differed between patients with constipation, diarrhea, or alternating bowel habit, with constipation-predominant IBS reporting the greatest severity and diarrhea the lowest. This study differs from the previous study in that patients were assessed with the IBSSS and were recruited

Distribution of Severity in Irritable Bowel Syndrome

An often quoted article on IBS severity by Drossman and Thompson2 estimated the prevalence of IBS severity as 70% mild, 25% moderate, and 5% severe. Patients with mild IBS were thought to be seen predominantly in primary care, to have symptoms that correlated well with physiologic factors (eg, eating, defecation, menses, etc), and to have little association with psychosocial distress or high health care use. Patients with moderate IBS were seen predominantly in secondary care. Patients with

Summary

IBS severity has important clinical and public health implications. However, few studies have been performed to address this issue, and, to date, no consensus criteria for assessing or defining IBS severity have been established. In the literature, IBS severity has been determined by a variety of factors including overall patient assessment, IBS symptoms, extraintestinal symptoms, pain behaviors such as healthcare seeking, health-related QOL, disability due to symptoms, and refractoriness to

References (42)

  • C.B. Dalton et al.

    Perceptions of physicians and patients with organic and functional gastrointestinal diagnoses

    Clin Gastroenterol Hepatol

    (2004)
  • D.A. Drossman et al.

    Health status by gastrointestinal diagnosis and abuse history

    Gastroenterology

    (1996)
  • D.A. Drossman et al.

    Cognitive-behavioral therapy versus education and desipramine versus placebo for moderate to severe functional bowel disorders

    Gastroenterology

    (2003)
  • A.D. Sperber et al.

    Use of the Functional Bowel Disorder Severity Index (FBDSI) in a study of patients with the irritable bowel syndrome and fibromyalgia

    Am J Gastroenterol

    (2000)
  • M. Schmulson et al.

    Symptom differences in moderate to severe IBS patients based on predominant bowel habit

    Am J Gastroenterol

    (1999)
  • O.Y. Lee et al.

    Gender-related differences in IBS symptoms

    Am J Gastroenterol

    (2001)
  • O. Palsson et al.

    IBS severity and health-related quality of life improve with age in women but not in men (abstr)

    Am J Gastroenterol

    (2003)
  • D.A. Drossma et al.

    AGA technical review on irritable bowel syndrome

    Gastroenterology

    (2002)
  • D.A. Drossman et al.

    The irritable bowel syndromereview and a graduated multicomponent treatment approach

    Ann Intern Med

    (1992)
  • A. Lembo et al.

    Alosetron in irritable bowel syndromestrategies for its use in a common gastrointestinal disorder

    Drugs

    (2003)
  • A.P. Manning et al.

    Towards positive diagnosis of the irritable bowel

    Br Med J

    (1978)
  • Cited by (88)

    • Efficacy of whole system ayurveda protocol in irritable bowel syndrome – A Randomized controlled clinical trial

      2023, Journal of Ayurveda and Integrative Medicine
      Citation Excerpt :

      The severity of symptoms of IBS varies from very mild to incapacitating. The prevalence of moderate and severe cases may be underestimated [4]. IBS has significant health care cost and burden, in USA cost of IBS management per year is more than US $ 1 billion and indirect costs are more than US $ 200 million [5].

    • 5.33 - Visceral Pain: From Bench to Bedside

      2020, The Senses: A Comprehensive Reference: Volume 1-7, Second Edition
    • Irritable Bowel Syndrome and Female Patients

      2016, Gastroenterology Clinics of North America
    View all citing articles on Scopus

    Supported in part by GlaxoSmithKline and by grants 1R01 AT01414-01 and 1R21 AT002860-01 from the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health (to A.L.).

    Drs Lembo and Drossman have served as consultants to GlaxoSmithKline. Dr Ameen is an employee of GlaxoSmithKline.

    View full text