By David S. MacDougall
Updated guidelines for the diagnosis and treatment of irritable bowel syndrome (IBS) in adults in primary care practice and other settings have been issued by the British Society of Gastroenterology (BSG).
IBS affects from 5% to 11% of the population of most countries, the guidelines state. Prevalence peaks in the 3rd and 4th decades, and women are disproportionately affected. IBS is well known to have a significant, negative impact on quality of life and generate substantial direct and indirect healthcare costs.
The condition is defined as a chronic, relapsing disorder characterized by:
In primary care practice, diagnostic investigation of patients with possible IBS should be reserved for those with "alarm features" (Table 1), say the guideline authors.
The BSG endorsed the Rome III criteria for the diagnosis of patients with IBS in clinical and research settings (Table 2). Recent attempts have been made to subclassify IBS according to the predominant bowel habit, with about one third of patients demonstrating diarrhea-predominant IBS, one third having constipation-predominant IBS, and the remaining patients having a mixed bowel pattern with both loose and hard stools.
At least one half of IBS patients can be described as depressed, anxious, or hypochondriacal. Other common comorbidities include fibromyalgia, chronic fatigue syndrome, temporomandibular joint disorder, and chronic pelvic pain.
Treatment recommendations for patients with IBS are based in part on the predominant underlying symptoms. Modification of diet and fiber intake have been used with some success, while avoiding lactose, carbohydrates, and other possible triggers may be useful in some patients.
Psychological therapies, including relaxation training, cognitive/behavioral therapy, and psychodynamic interpersonal therapy, should be considered in patients who have marked anxiety or depressive symptoms. Hypnotherapy, which may be helpful in patients with refractory disease, offers the advantages of long-lasting effects and improvements in quality of life and psychological status.
Table 1. IBS alarm features
1. Age >50 years
2. Short history of symptoms
3. Documented weight loss
4. Nocturnal symptoms
5. Male gender
6. Family history of colon cancer
8. Rectal bleeding
9. Recent antibiotic usage
Potential pharmacotherapies for patients with IBS include antispasmodics, antidepressants, antidiarrheals, 5-HT4 receptor agonists, 5-HT3 receptor antagonists, antibiotics, and probiotics. But only a minority of patients benefit from pharmacotherapy, the authors note. The optimum approach is to start with the safest and least-expensive drugs.
Management of patients with IBS in primary care involves setting therapeutic goals, patient education on self-management, and identifying barriers that may interfere with implementing the guideline recommendations.
The complete guidelines are published in Gut: Spiller R, Aziz Q, Creed F, et al. Guidelines for the management of irritable bowel syndrome. Gut. Online before print. 2007 May 8.
Table 2. Rome III Diagnostic Criteria* for IBS
Recurrent abdominal pain or discomfort at least 3 days/month in the past 3 months associated with 2 of the following:
• Improvement with defcation
• Onset associated with a change in frequencey of stool
• Onset associated with a change in form (appearance) of stool.
*Criteria fulfilled when the diagnostic criteria have occurred for the past 3 months with symptom onset at least 6 months before diagnosis.