Introduction: Whether dietary fructose intolerance causes symptoms of irritable bowel syndrome (IBS) is unclear. We examined the prevalence of fructose intolerance in IBS and long-term outcome of fructose-restricted diet.
Methods: Two hundred and nine patients with suspected IBS were retrospectively evaluated for organic illnesses. Patients with IBS (Rome II) and positive fructose breath test received instructions regarding fructose-restricted diet. One year later, their symptoms, compliance with, and effects of dietary modification on lifestyle were assessed using a structured interview.
Results: Eighty patients (m/f=26/54) fulfilled Rome II criteria. Of 80 patients, 31 (38%) had positive breath test. Of 31 patients, 26 (84%) participated in follow-up (mean=13 mo) evaluation. Of 26 patients, 14 (53%) were compliant with diet; mean compliance=71%. In this group, pain, belching, bloating, fullness, indigestion, and diarrhea improved (P<0.02). Of 26 patients, 12 (46%) were noncompliant, and their symptoms were unchanged, except belching. The mean impact on lifestyle, compliant versus noncompliant groups was 2.93 versus 2.57 (P>0.05).
Conclusions: About one-third of patients with suspected IBS had fructose intolerance. When compliant, symptoms improved on fructose-restricted diet despite moderate impact on lifestyle; noncompliance was associated with persistent symptoms. Fructose intolerance is another jigsaw piece of the IBS puzzle that may respond to dietary modification.
*Immanuel St Joseph's, Mayo Health System, Mankato, MN
†Department of Internal Medicine
‡Clinical Research Center, University of Iowa Carver College of Medicine, Iowa City, IA
The authors declare no conflict of interest.
Supported in part by NIH RO1 grant DK 57100-05 and grant RR00059 from the General Clinical Research Centers program, National Center for Research Resources.
Reprints: Satish S.C. Rao, MD, PhD, FRCP, Department of Internal Medicine, University of Iowa Hospitals and Clinics, 200 Hawkins Drive/4612 JCP, Iowa City, IA 52242-1009 (e-mail: firstname.lastname@example.org).
Received for publication August 23, 2006; accepted October 20, 2006