Infections Could Be the Trigger for IBS, Chronic Indigestion: Study

Certain risk factors, including anxiety, may cause lingering gut symptoms in those who’ve had COVID-19 and certain bacterial infections.

IBS is a chronic disorder that affects the large intestine and causes symptoms such as abdominal pain, cramping, constipation, and diarrhea.fizkes/Shutterstock

A new study adds to research that shows irritable bowel syndrome can persist for months and even years in those suffering from particular bacterial and viral stomach infections.

Published on July 16 in Gut, the review and meta-analysis noted that 14.5 percent of those suffering from gastroenteritis developed irritable bowel syndrome (IBS), and 13 percent from the same pool of 14,446 people experienced functional dyspepsia, or chronic heartburn.

Among those with IBS, symptoms persisted for one to four years in 52 percent of the population in three studies and beyond five years for 40 percent of participants in four studies. IBS symptoms include stomach pain, bloating, and irregular bowel habits of either chronic constipation, diarrhea, or both.

Additionally, those in the review who had gastroenteritis were more than four times as likely to develop IBS and three times as likely to develop dyspepsia compared with those in the research who didn’t have gastroenteritis.

Specific Bugs Implicated

The researchers acknowledge that while IBS and dyspepsia causes are not fully understood, about 179 million people worldwide experience gastroenteritis every year. These infections are often brought on by a viral stomach bug or food poisoning, which may be caused by bacteria, parasites, viruses, or other toxins.

The relationship between IBS/dyspepsia and gastroenteritis, especially as it relates to more aggressive and pro-inflammatory bacteria and the virus responsible for COVID-19, can be important information for doctors dealing with patients who have ongoing symptoms after a recent gastroenteritis infection.

Disorders such as IBS and chronic heartburn “are traditionally perceived by healthcare professionals as being mostly psychological and less ‘valid’ diseases, with a potential risk of underestimating patients’ expectations and complaints,” the authors wrote in the study.

“Generally, as acute gastroenteritis is a common disorder worldwide, our findings may be relevant for public health, and physicians should pay heed if their patients present with a recent episode of infectious gastroenteritis.”

The causes of gastroenteritis noted in the study were parasites at 30 percent, bacteria at 18 percent, and viruses at nearly 11 percent.

Those with the highest incidence of IBS following gastroenteritis experienced diarrhea-causing Campylobacter bacterial infections. Additionally, those infected with SARS-CoV-2, the virus that causes COVID-19, or parasites were five times as likely to develop IBS.

About 10 percent of those experiencing functional dyspepsia had also first been infected with SARS-CoV-2.

A Persisting Tale

A study published in 2010 in Gut that followed 742 people to learn more about the long-term effects of acute gastroenteritis noted a similar trend. The subjects had been involved in a municipal water contamination outbreak. Eight years after their initial assessment, more than 28 percent of the subjects still suffered from IBS after two to three years, and 15.4 percent had IBS after eight years.

The link between campylobacter and post-infectious IBS (PI-IBS) is also well established, though it may not be well-known among clinicians, according to Dr. Madhusudan Grover, a gastroenterologist and researcher at Mayo Clinic.

“Clinicians need to be aware of this entity so that patients can be properly counseled and treated and avoid unnecessary testing,” Dr. Grover said in a statement. “It is important to remember that females, younger individuals, and those who had bloody stools, abdominal cramps and hospitalization during acute enteritis are at a greater risk of developing PI-IBS.”

Post-infectious IBS is becoming more notable with COVID-19 appearing to contribute to cases. A 2023 review in Brazil suggested the virus could be associated with IBS—in part due to its contribution to dysbiosis or an imbalance in microbiota.

“Individuals who developed IBS may have been unable to overcome post-infectious dysbiosis,” the study noted. “Finally, psychological components such as stress, anxiety, and depression are also considered predisposing to post-COVID-19 IBS.”

Risk factors in this research were: female, severity of COVID-19, presence of acute gastrointestinal symptoms, and depression/anxiety.

Certain People More at Risk

Similar risks appeared in the new review and meta-analysis. Specific risk factors for developing IBS after a stomach bug were being female, having diarrhea lasting more than three weeks, and a history of anxiety. The latter risk factor was associated with a three-fold risk.

Anxiety on its own can change the makeup of the gut microbiome, according to the University of Chicago Medicine. The gut-brain connection includes the gut’s role in releasing hormones and neurotransmitters, a physiological response that can be negatively affected when there aren’t sufficient microbes to make the short-chain fatty acids that contribute to hormone and neurotransmitter production. That can slow down gut motility and function, including fortifying the intestinal barrier against inflammatory toxins that may enter the bloodstream.

Temporary bouts of stress may cause stomach pain and short-term symptoms that subside as the stressors dissipate. Chronic anxiety, however, can create bothersome IBS symptoms such as constipation, bloating, and diarrhea, University of Chicago Medicine explained in their article.

Lessening Risks

The University of Chicago Medicine suggests the following tips for dealing with stress and anxiety:

• Move regularly; avoid long periods of sitting
• Try relaxing breathing exercises
• Take short breaks, especially during stressful activities
• Sleep seven hours nightly
• Eat whole food rather than processed food
• Abstain or minimize alcohol
• Spend time with others
• Get out in nature
• Meditate
• Talk to a friend, therapist, or a social worker about your stressors

Some precautions may also minimize the risk of stomach bugs. Washing hands frequently may also cut down on 47 percent of gastroenteritis cases, according to a 2003 review in The Lancet. Additionally, using safe food preparation protocols for handling, storing, and cooking raw items can minimize contamination.