Did Your Gut Issues Start After Food Poisoning or a Stomach Bug?

Most of us have experienced food poisoning or a stomach bug at some point. While the symptoms usually pass once the infection clears, for some people, gut issues linger—leading to chronic bloating, gas, and diarrhea.

This condition, known as post-infectious IBS (PI-IBS), is more common than you might think. Here’s how it happens:

The bacteria and viruses that cause food poisoning release toxins called Cytolethal Distending Toxin (CdtB). In response, your immune system produces anti-CdtB antibodies—a normal defense mechanism. However, CdtB closely resembles a beneficial gut protein called vinculin. Sometimes, the immune system mistakes vinculin for CdtB and begins producing anti-vinculin antibodies, attacking the body’s own gut-supporting proteins.

This autoimmune response can damage gut nerves and disrupt key functions like the Migrating Motor Complex (MMC) and Interstitial Cells of Cajal (ICC), which regulate digestion. When these functions are impaired, gut motility slows down, the microbiome becomes imbalanced, and chronic symptoms—often diagnosed as IBS—develop. In many cases, this also sets the stage for SIBO (Small Intestinal Bacterial Overgrowth), a condition commonly linked to post-infectious IBS.

What This Means for You

If your gut symptoms began after food poisoning or a stomach bug, understanding this connection can help guide treatment. Many people don’t realise their lingering gut issues are linked to an infection that happened weeks, months, or even years ago.

In my clinic, I often see clients whose symptoms started after traveling abroad and getting food poisoning or after recovering from a stomach virus. In these cases, I frequently recommend SIBO testing and a gut-healing protocol focused on restoring microbial diversity and immune balance. Supporting beneficial gut bacteria is key to long-term recovery.

Can You Recover from Post-Infectious IBS?

Yes! Despite the common belief that IBS has no cure, post-infectious IBS can improve with the right approach and support. By addressing the underlying gut dysfunction, many people experience significant relief.

A Similar Pattern with Viral Infections

Interestingly, we are seeing a similar trend with viruses like Covid-19 and Epstein Barr Virus. While research is still emerging, many viral infections appear to trigger post-viral IBS in the same way food poisoning does. Clinically, I’ve seen numerous clients develop chronic gut symptoms after a COVID infection or mononucleosis (mono), and I expect future research will confirm this connection.

If you suspect post-infectious IBS, don’t ignore your symptoms—getting the right support can make all the difference.