Related Experiment Video
Updated: May 29, 2026
Chronic Salmonella Infection Induced Intestinal Fibrosis
Published on: September 22, 2019
Irritable bowel syndrome and chronic fatigue 3 years after acute giardiasis: historic cohort study
Knut-Arne Wensaas1, Nina Langeland, Kurt Hanevik
1Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway. knut-arne.wensaas@uni.no
Background:
Giardia lamblia is a common cause of gastroenteritis worldwide, but there is limited knowledge about the long-term complications.
Objective:
To estimate the relative risk of irritable bowel syndrome (IBS) and chronic fatigue 3 years after acute giardiasis.
Design:
Controlled historic cohort study with 3 years' follow-up. Data collected by mailed questionnaire.
Setting:
Waterborne outbreak of giardiasis in the city of Bergen, Norway.
Participants:
817 patients exposed to Giardia lamblia infection verified by detection of cysts in stool samples and 1128 matched controls.
Main Outcome Measures:
IBS and chronic fatigue.
Results:
The prevalence of IBS in the exposed group was 46.1%, compared with 14.0% in the control group, and the adjusted RR=3.4 (95% CI 2.9 to 3.8). Chronic fatigue was reported by 46.1% of the exposed group and 12.0% of the controls, the adjusted RR was 4.0 (95% CI 3.5 to 4.5). IBS and chronic fatigue were associated and the RR for the exposed group of having a combination of the two outcomes was 6.8 (95% CI 5.3 to 8.5). The RR was also increased for having just one of the two syndromes, 1.8 for IBS (95% CI 1.4 to 2.3) and 2.2 for chronic fatigue (95% CI 1.7 to 2.8).
Conclusions:
Infection with Giardia lamblia in a non-endemic area was associated with a high prevalence of IBS and chronic fatigue 3 years after acute illness, and the risk was significantly higher than in the control group. This shows that the potential consequences of giardiasis are more serious than previously known. Further studies are needed, especially in areas where giardiasis is endemic.
Related Concept Videos
01:12Giardiasis
01:17Chronic Bowel Disorders: Introduction
Irritable Bowel Syndrome (IBS) is a common disorder affecting the gastrointestinal tract. The distinctive feature is recurrent abdominal pain associated with altered bowel movements, manifesting as constipation, diarrhea, or fluctuating between both. The...
01:30Irritable Bowel Syndrome II: Clinical Features and Diagnostic Evaluation
Irritable Bowel Syndrome (IBS) is classified into subtypes based on the predominant bowel habits as determined by the Bristol Stool Form Scale (BSFS). The subtypes are:
01:17Irritable Bowel Syndrome I: Introduction
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...
01:25Inflammatory Bowel Disease III: Crohn's Disease
01:23Irritable Bowel Syndrome