Am Fam Physician. 2006;74(4):557
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
| Manning criteria | ||
| IBS is diagnosed if three of the following are present: | ||
| Abdominal pain | ||
| Pain relief with defecation | ||
| Increased stool frequency with pain | ||
| Looser stools with pain | ||
| Mucus in stools | ||
| Feeling of incomplete evacuation | ||
| Rome I criteria | ||
| IBS is diagnosed if the following are present: | ||
| At least three months of continuous or recurrent abdominal pain that is relieved with defecation and/or is associated with a change in stool consistency | ||
| Plus, at least two of the following on at least 25 percent of days: | ||
| Altered stool frequency | ||
| Altered stool form or passage | ||
| Passage of mucus | ||
| Bloating or feeling of abdominal distension | ||
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 f lag 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.
editor’s note: This letter was sent to the authors of “Treatment of Irritable Bowel Syndrome,” who declined to reply.