A link between irritable bowel syndrome and fibromyalgia may be related to findings on lactulose breath testing.
BACKGROUND
An association between irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) has been found.


OBJECTIVE
To compare the prevalence and test results for bacterial overgrowth between IBS and fibromyalgia.


METHODS
Subjects with independent fibromyalgia and IBS were compared with controls in a double blind study. Participants completed a questionnaire, and a lactulose hydrogen breath test was used to determine the presence of SIBO. The prevalence of an abnormal breath test was compared between study participants. Hydrogen production on the breath test was compared between subjects with IBS and fibromyalgia. The somatic pain visual analogue score of subjects with fibromyalgia was compared with their degree of hydrogen production.


RESULTS
3/15 (20%) controls had an abnormal breath test compared with 93/111 (84%) subjects with IBS (p<0.01) and 42/42 (100%) with fibromyalgia (p<0.0001 v controls, p<0.05 v IBS). Subjects with fibromyalgia had higher hydrogen profiles (p<0.01), peak hydrogen (p<0.0001), and area under the curve (p<0.01) than subjects with IBS. This was not dependent on the higher prevalence of an abnormal breath test. The degree of somatic pain in fibromyalgia correlated significantly with the hydrogen level seen on the breath test (r = 0.42, p<0.01).


CONCLUSIONS
An abnormal lactulose breath test is more common in fibromyalgia than IBS. In contrast with IBS, the degree of abnormality on breath test is greater in subjects with fibromyalgia and correlates with somatic pain.
Pimentel
M
M
GI Motility Program, Divisions of Gastroenterology and Rheumatology, Department of Medicine, Cedars-Sinai Medical Center, CSMC Burns & Allen Research Institute, Los Angeles, California 90048, USA.
Wallace
D
D
Hallegua
D
D
Chow
E
E
Kong
Y
Y
Park
S
S
Lin
H C
HC
D001944:Breath Tests / Q000379:methods; D004311:Double-Blind Method; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000382:microbiology*; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D007421:Intestine, Small / Q000382:microbiology; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000382:microbiology*; D007792:Lactulose; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D007792:Lactulose; D006859:Hydrogen