Post-Infectious Irritable Bowel Syndrome

Epidemiology and Diagnosis of PI-IBS

Approximately 10.1% of patients develop PI-IBS within 12 months following infectious enteritis, with prevalence increasing to 14.5% beyond 12 months 3, 4
Patients with PI-IBS have a 4.2-fold increased risk of developing IBS compared to uninfected individuals within 12 months, which decreases to 2.3-fold beyond 12 months 5, 6
In typical cases of PI-IBS without alarm features, physicians are encouraged to make a positive diagnosis without extensive additional diagnostic assessment 1, 7
Only a minority of PI-IBS cases undergo fecal tests to exclude chronic parasitic or protozoal infections, particularly giardiasis 2, 8
Stool cultures rarely yield positive results as long-lasting infections with Campylobacter, Shigella, Salmonella, or Yersinia are uncommon 1, 7

Bacterial infections (particularly Campylobacter, Salmonella, Shigella, and C. difficile) carry a higher risk of developing PI-IBS compared to viral infections 10, 6
The prevalence of PI-IBS among those suffering from infectious enteritis ranges between 4-36%, with significant variation based on pathogen type and geographic location 9

PI-IBS is a complex, multifactorial disorder involving interactions between central and peripheral factors 5, 6
Key mechanisms include altered gut microbiota composition 5, 6
Visceral hypersensitivity and gut dysmotility may also play a role 4

Most patients with PI-IBS present with either diarrhea-predominant IBS (IBS-D) or mixed bowel habit (IBS-M) subtypes 2, 8
The IBS-D subtype tends to remain stable over time, while other subtypes may experience phenotypic switches 2, 8
Overlap with other functional gastrointestinal disorders, particularly functional dyspepsia, is common (occurring in up to 50% of cases) 6