Postinfectious Irritable Bowel Syndrome: Causes, Symptoms, and Treatment

Irritable bowel syndrome, or IBS, can be uncomfortable to say the least. Symptoms such as abdominal pain, bloating, and diarrhea may suddenly appear or disappear, affecting work and life.

The same is true for post-infectious irritable bowel syndrome (IBS), which has many of the same symptoms but different causes and triggers.

Treating post-infectious irritable bowel syndrome may also look similar, but there are some subtle differences to keep in mind.

Here, learn everything you need to know about post-infectious irritable bowel syndrome, including its duration and treatment options.

Postinfectious IBS (or PI-IBS) is a subgroup of IBS that occurs only after an infection, usually gastroenteritis (aka the “stomach flu”) or food poisoning. But any type of infection (bacterial, viral, or parasitic) that inflames the lining of the stomach can also cause the condition, according to the U.S. National Library of Medicine (NLM).

If your gastrointestinal symptoms (such as abdominal pain, diarrhea, gas, and bloating) persist after the infection has been treated and resolved, you may have PI-IBS.

It turns out that roughly 10 to 15 percent of Americans suffer from IBS, according to the NLM, but an April 2021 studyNorth American Gastroenterology Clinics‌It was found that more than half of these cases may actually be PI-IBS.

Remember, diarrhea is a common side effect of antibiotics, according to the Cleveland Clinic. However, it is usually mild, transient, and does not involve the significant bloating, pain, and discomfort associated with PI-IBS.

As with “regular” IBS, no one knows exactly why PI-IBS occurs. But Sarah Robbins, M.D., a gastroenterologist in British Columbia, says some of the following factors may increase your risk of developing the disease:

• severe infection
• prolonged fever
• Use antibiotics during illness
• Anxiety, depression and other psychological factors
• The balance of good and bad bacteria is disrupted, called dysbiosis
• Immune system changes that affect gut function
• persistent intestinal inflammation

“PI-IBS is more likely to be caused by changes in our gut microbiome than regular IBS, which is most often affected by the food we eat and stress,” says New Jersey board-certified gastroenterologist says scientist Andrew Boxer, MD.

Unlike chronic IBS, which often requires lifelong symptom management, PI-IBS is usually temporary.

The duration of PI-IBS is different for everyone. “Sometimes, it only lasts a few days, but most often, it can last several weeks…even one to two months,” Dr. Boxer said.

In rare cases, PI-IBS can even last for years. For example, Dr. Boxer treated veterans who developed gastrointestinal infections while overseas but returned with PI-IBS that persisted for years after the infection.

In fact, “approximately 25% of patients with bacterial gastroenteritis report persistent IBS symptoms 6 months after infection,” says Dr. Robbins. “While some patients’ symptoms resolve within a year, others have symptoms that persist for years.”

Over time, it can be difficult to tell whether you have chronic IBS or PI-IBS, Dr. Robbins says. If this continues, gastroenterologists will change their strategy and focus on relieving symptoms rather than curing the condition, regardless of what caused it in the first place.

Dr. Robbins adds that some other factors that may cause PI-IBS to last longer include a severe initial infection, or the presence of depression and anxiety.

In fact, irritable bowel syndrome and anxiety are closely related and are sometimes treated in a similar manner through the University of North Carolina Center for Functional Gastrointestinal and Motility Disorders, through relaxation techniques or antidepressant medications.

Fortunately, PI-IBS is treatable, and symptoms can be managed in a number of different ways. Treatment is similar to regular IBS.

Dr. Robbins said the focus of treatment may involve healing the gut microbiome, but most often is “just relieving symptoms.” “Treatments can include dietary changes, medications, probiotics, behavioral therapy and talk therapy,” she adds.

Dr. Robbins recommends the following to his patients:

For many people with IBS, the low-FODMAP diet is a helpful tool. According to Johns Hopkins University Medical Center, FODMAPs (or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are short-chain carbohydrates (sugar) that are difficult to digest in the small intestine.

According to Johns Hopkins Medicine, some foods rich in FODMAPs include:

• Dairy products such as yogurt and ice cream
• Wheat-based products such as cereals, breads and crackers
• beans
• some vegetables, such as asparagus, onions, and garlic
• some fruits, such as apples, cherries, pears, and peaches

A low-FODMAP diet can help reduce the symptoms of PI-IBS and regular IBS. According to Johns Hopkins Medicine, some low-FODMAP foods include the following:

• Egg
• meat and seafood
• almond milk
• rice
• Quinoa
• Potato
• eggplant
• Grape
• blueberry

Dr. Robbins says research is limited, and most don’t differentiate between idiopathic (conventional) IBS and PI-IBS, but there is some evidence that probiotics may help reduce PI-IBS symptoms after an episode of gastroenteritis.

Based on an earlier review from August 2013indian journal of medical research‌, there is not enough strong evidence of the benefits of probiotics to recommend it as ‌basic‌ Treating IBS, but combining certain strains of bacteria (such as Lactobacillus and Bifidobacterium) may help people experience an overall improvement in symptoms.

“Probiotics are generally well tolerated and safe for most people,” says Dr. Robbins. But you should still consult your doctor before taking them, especially if you have any underlying health conditions.

If other lifestyle changes don’t help, there are several different types of medications that can be considered for short-term treatment of PI-IBS symptoms. These include the following from Dr. Robbins:

• ‌‌Antispasmodics:‌ Dicyclomine (Bentyl) and hyoscyamine can reduce abdominal pain in the short term. These are prescribed by your doctor.
• ‌‌Antidiarrheal:‌ Imodium can be used by people who need help with diarrhea.
• ‌‌laxative:‌ MiraLax or Dulcolax can be used by people who need help relieving constipation.
• ‌‌Antidepressants:‌ Low doses of tricyclic antidepressants (such as amitriptyline) or SSRIs (such as paroxetine) can surprisingly help control abdominal pain and bowel habits. These can be prescribed by your doctor.

Life with PI-IBS can be stressful. Even the thought of experiencing an attack can exacerbate your anxiety, which in turn can worsen your gastrointestinal symptoms.

This is why managing your emotions is crucial. Reducing stress through relaxation techniques such as deep breathing, yoga, and meditation can help in daily life. Additionally, finding a therapist to help you talk through your emotions can be a beneficial experience for both PI-IBS and the long-term management of IBS.

Cognitive behavioral therapy (or CBT) has been rigorously tested in clinical trials and continues to demonstrate lasting improvements in IBS symptoms, according to a July 2017 review.Psychological Research and Behavior Management‌.This therapy can help you change the way you think about stress and situations.

A small study from January 2015world journal of gastroenterology‌ Increased physical activity was found to be associated with positive long-term effects on irritable bowel syndrome symptoms and psychological symptoms associated with the disease.

But remember, when you’re recovering from an infection, it’s best to take your time. Start with gentle exercise like yoga, stretching, or walking. You can then increase your physical activity level based on the severity and frequency of your PI-IBS symptoms.

(Sometimes exercise can stimulate bowel movements, which is not ideal for people with PI-IBS diarrhea.)

You may be experiencing PI-IBS symptoms because your gastrointestinal infection has not healed. In this case, your doctor can order stool samples and other tests to determine if the infection is still present, and then prescribe antibiotics accordingly.

Rifaximin is a nonabsorbable antibiotic often prescribed by the Mayo Clinic to treat infections such as E. coli and, in some cases, to treat irritable bowel syndrome.

Whenever your bowel habits change and cause pain or discomfort, it may be worth seeing your doctor to determine the cause. If you experience diarrhea, bloating, and/or constipation after a gastrointestinal infection, you may have PI-IBS and may benefit from any of the treatments listed above.

“Any unusual signs and symptoms you experience should be reported to your doctor,” Dr. Boxer says.

Watch for signs of weight loss, blood in the stool, fatigue, fainting, difficulty swallowing, diarrhea for several weeks without regular bowel movements, nausea, vomiting, and pain while eating. These may indicate that you are dealing with a more serious health problem that may require immediate medical attention or a test, such as a colonoscopy, endoscopy, or MRI.

Ultimately, PI-IBS itself is not life-threatening and can be managed. Be patient and work through the effects of the infection, and always talk to your doctor if you have concerns.