Letters to the Editor

Diagnostic Criteria for Patients with Irritable Bowel Syndrome

TO THE EDITOR: Drs. Hadley and Gaarder provide a helpful discussion of irritable bowel syndrome (IBS) in their article1 in the December 15, 2005, issue of American Family Physician. I would like to add further clarification to two points regarding the diagnosis of IBS. First, although the Rome II diagnostic criteria listed in the article1 are commonly used in discussions of IBS, they have been found to be insensitive for the diagnosis of IBS in clinical practice2 and unreliable for capturing disease fluctuation over time.3 The Manning and Rome I criteria for diagnosis of IBS (see accompanying table) have been subjected to more study and validation.4,5 The presence of three of the six Manning criteria is 63 to 90 percent sensitive and 70 to 93 percent specific for diagnosing IBS if no "red flag" symptoms (weight loss, hematochezia, anemia, fever, or onset of symptoms after 50 years of age) are present.4

Second, it should be emphasized that IBS is not a "diagnosis of exclusion" that can be applied only after other testing has been exhausted. Rather, IBS can be positively diagnosed and further testing avoided for patients who meet diagnostic criteria (such as Manning or Rome I) and have no red flag symptoms. This approach is supported by a meta-analysis6 of six studies that found that endoscopy, ultrasonography, and barium studies only detected organic disease in approximately 1 percent of patients who otherwise met IBS diagnostic criteria, and blood counts and chemistries were unhelpful in further clarifying the diagnosis. Proper use of diagnostic criteria for IBS can facilitate more timely diagnosis, avoid needless testing that is unlikely to reveal organic pathology, and facilitate more prompt initiation of a therapeutic relationship and institution of treatment.

William E. Cayley, Jr., M.D. M.Div.

Eau Claire Family Medicine Residency
University of Wisconsin
Dept. of Family Medicine
207 W. Lincoln
Augusta, WI 54722

REFERENCES

1. Hadley SK, Gaarder SM. Treatment of irritable bowel syndrome. Am Fam Physician 2005;72:2501-6.

2. Lea R, Hopkins V, Hastleton J, Houghton LA, Whorwell PJ. Diagnostic criteria for irritable bowel syndrome: utility and applicability in clinical practice. Digestion 2004;70:210-3.

3. Williams RE, Black CL, Kim HY, Andrews EB, Mangel AW, Buda JJ, et al. Stability of irritable bowel syndrome using a Rome II-based classification. Aliment Pharmacol Ther 2006;23:197-205.

4. Fass R, Longstreth GF, Pimentel M, Fullerton S, Russak SM, Chiou CF, et al. Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome. Arch Intern Med 2001;161:2081-8.

5. Longstreth GF. Definition and classification of irritable bowel syndrome: current consensus and controversies. Gastroenterol Clin North Am 2005;34:173-87.

6. Cash BD, Schoenfeld P, Chey WD. The utility of diagnostic tests in irritable bowel syndrome patients: a systematic review. Am J Gastroenterol 2002;97:2812-9.

editor's note: This letter was sent to the authors of "Treatment of Irritable Bowel Syndrome," who declined to reply.

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