Irritable bowel syndrome is a chronic condition that affects the gastrointestinal (GI) tract. Post-infectious IBS happens when a person suddenly develops IBS symptoms after an infection.

Irritable bowel syndrome (IBS) is a common condition that causes persistent changes to a person’s bowel habits. It is typically caused by stress, sensitive nerves in the gut, or a family history.

But another type of IBS can occur after a person has an infection.

Here’s what you need to know about post-infectious IBS, sometimes called PI-IBS in the medical community. We’ll include a look at what treatments may help and how long the condition may last.

IBS is a group of intestinal issues that can cause cramping.

PI-IBS is a type that starts after an infection, usually within 2 to 3 years. This condition is most often caused by bacterial, viral, or parasitic infections in the gut, like acute gastroenteritis (AGE).

Researchers estimate the prevalence of PI-IBS in the United States to be about 9%. That’s just about half of all reported cases of IBS.

Studies show that the severity of a person’s AGE infection is directly related to the potential of developing PI-IBS. Most people who developed this condition experienced diarrhea and other stool symptoms for more than a week with their initial infection.

The collective prevalence of people developing PI-IBS after AGE is around 11.5%. People with chronic bowel dysfunction after infection are also more likely to develop PI-IBS and functional dyspepsia.

In addition to gut infections, researchers have recently discovered that some people may develop PI-IBS after having COVID-19.

Other than infection, there are additional risk factors that may make developing PI-IBS more likely. They include:

Other risk factors include:

The symptoms of PI-IBS are similar to those of IBS. The primary difference is the onset — PI-IBS always begins after infection. You may experience abdominal pain and cramping worse after eating and better after going to the bathroom.

Other symptoms may include:

It’s important to note that fever or vomiting are not part of the diagnostic criteria with standard IBS. Instead, they are unique features of PI-IBS. And people who may have PI-IBS after COVID-19 may not have issues with constipation.

You may also experience flares of your symptoms (good days, bad days) or a worsening of your symptoms triggered by certain foods or beverages.

Consider immediate medical attention if …

You may need immediate medical attention if you experience any of the following symptoms.

These may be a sign that you have another condition or that you are experiencing life threatening complications from your original infection.

Was this helpful?

The duration of PI-IBS varies by person. For some people, symptoms may subside in 1 year. For others, it may last longer. How long symptoms last is individual and cannot be predicted.

Studies show that PI-IBS caused by viral infections go away more quickly than those caused by bacterial infections.

IBS occurs without any apparent trigger. But once IBS develops, whether post-infectious or not, it often becomes chronic. Though IBS can be managed, there is no specific cure for any form of IBS.

Experts don’t know exactly what causes IBS, but it may be caused by stress, family history of IBS, nerve oversensitivity in the gut, or food moving through it too quickly or slowly.

Lifestyle changes, such as dietary modifications, may help with PI-IBS. Your doctor may also suggest over-the-counter (OTC) medications to lessen your symptoms during a flare.

Other treatments include:

Undergoing a fecal microbiota transplant (FMT) is another possible treatment. In this procedure, the stool from a person without IBS is transferred to the colon of the person with PI-IBS.

In one study, FMT was effective in treating PI-IBS caused by giardia (a parasitic infection), but only for 7 weeks before symptoms returned.

With or without treatment, PI-IBS can improve over time.

At the 1-year mark, 19.7% of people report recovery from PI-IBS. Recovery rates are lower in some groups, like women, people with somatic symptom disorder, and people who live in North America or Northern Europe.

Research suggests that the rates of PI-IBS may increase up until the 3-year mark after infection and fall after that time.

For some, symptoms may last for several more years. One long-term study revealed that 15% of people still had PI-IBS 8 years after symptom onset.

PI-IBS may be responsible for up to half of all IBS cases. Talk with a doctor if you are experiencing persistent GI symptoms after an acute infection like AGE. They can diagnose your gut issues and suggest possible treatments that could improve your quality of life.