Stability of Classification Systems for Irritable Bowel Syndrome

Area of Science:

• Gastroenterology
• Psychiatry
• Clinical Research

Background:

• Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder.
• Current IBS classification relies on stool form but symptom patterns are dynamic.
• This fluctuation presents challenges for effective subtype-based management.

Purpose of the Study:

• To evaluate the 12-month stability of four distinct Irritable Bowel Syndrome (IBS) classification methods.
• Assessing stability using stool form, most troublesome symptom, and two latent class analyses (LCA) models.
• Investigating a comprehensive LCA including gastrointestinal and psychological symptoms, and a simplified LCA based on psychological burden.

Main Methods:

• Recruitment of participants meeting Rome IV criteria for IBS from a UK registry.
• Administration of validated online questionnaires assessing gastrointestinal and psychological symptoms at baseline and 12 months.
• Evaluation of classification stability using Cohen's kappa statistic.

Main Results:

• Stool form-based subtyping demonstrated the highest stability (κ=0.60), with 83% of diarrhea-predominant IBS cases remaining stable.
• Classification based on psychological burden also showed moderate stability (κ=0.54).
• Latent class analysis (LCA) methods, particularly the seven-cluster model (κ=0.37), exhibited lower stability over the 12-month period.

Conclusions:

• Existing IBS classification systems exhibit only moderate stability over 12 months, reflecting the disorder's inherent variability.
• Stool form and psychological burden appear to be the most stable classification parameters.
• Future research should focus on dynamic models integrating both gastrointestinal and psychological factors for improved IBS management.