Most people have experienced food poisoning or a stomach virus at some point. While symptoms typically resolve once the infection passes, some individuals find that digestive issues persist—leading to chronic bloating, gas, and diarrhoea.

This condition, known as post-infectious IBS (PI-IBS), is more common than many realise. Here’s how it develops:

The bacteria and viruses responsible for food poisoning release toxins, including Cytolethal Distending Toxin (CdtB). In response, the immune system produces anti-CdtB antibodies to fight off the infection. However, CdtB closely resembles vinculin, a crucial gut-supporting protein. In some cases, the immune system mistakenly attacks vinculin, producing anti-vinculin antibodies that disrupt gut function.

This autoimmune response can damage the nerves in the gut, impairing key functions such as the Migrating Motor Complex (MMC) and Interstitial Cells of Cajal (ICC), which help regulate digestion. When these systems are compromised, gut motility slows, the microbiome becomes imbalanced, and persistent digestive symptoms—often diagnosed as IBS—develop. This imbalance also increases the likelihood of SIBO (Small Intestinal Bacterial Overgrowth), a condition frequently linked to post-infectious IBS.

What This Means for You

If your digestive symptoms began after a bout of food poisoning or a stomach virus, recognising this connection can be the first step toward effective treatment. Many people don’t realise that a past infection—even from weeks, months, or years ago—could be the root cause of their ongoing gut issues.

In my practice, I frequently see clients whose symptoms started after traveling abroad and experiencing food poisoning or following a stomach virus. In these cases, I often recommend SIBO testing and a targeted gut-healing approach focused on restoring microbial diversity and immune balance. Supporting beneficial gut bacteria is essential for long-term digestive health.

Can You Recover from Post-Infectious IBS?

Absolutely! While IBS is often labeled as a chronic condition with no cure, post-infectious IBS can improve significantly with the right approach. By addressing underlying gut dysfunction, many individuals experience noticeable relief and a return to normal digestion.

A Similar Pattern with Viral Infections

Interestingly, similar trends are emerging with viral infections like Epstein-Barr Virus. While research is still ongoing, many viruses appear to trigger post-viral IBS in the same way bacterial infections do. Clinically, I’ve worked with numerous clients who developed chronic digestive symptoms following viral infection, and I anticipate that future research will continue to confirm this link.

If you suspect that post-infectious IBS may be affecting you, don’t ignore your symptoms—seeking the right support can be a game-changer for your gut health and overall well-being.