A nasty bout of food poisoning or viral gastroenteritis can leave anyone feeling wiped out for a few days, but for some people it doesn’t end when the bug has cleared. A subset of patients will go on to develop long-lasting bowel problems including abdominal pain, unpredictable diarrhoea, and bloating.
When IBS first appears after an infection, doctors call it post-infectious IBS (PI-IBS), and research suggests it may account for almost half of all IBS diagnoses.
Below, we’ll explore how IBS develops after an infection, the symptoms that set it apart, and the practical steps to get relief.
From bug to bowel trouble: How PI-IBS develops
PI-IBS follows an episode of acute gastrointestinal infection, most often bacterial food poisoning (think Campylobacter or Salmonella) but also viral or parasitic illnesses. In the weeks that follow, lingering inflammation, shifts in the gut microbiome, and heightened sensitivity of the intestinal nerves, can combine to keep the bowels in turmoil.
Research shows that around 11 per cent of people who experience an acute gut infection will develop PI-IBS, and the risk climbs if the original illness caused severe diarrhoea lasting more than a week. Being female, under 40, or experiencing significant stress or anxiety at the time of the infection also seem to increase susceptibility.
Recently, several studies have reported a similar pattern after SARS-CoV-2 infection. While most people think of COVID as a respiratory illness, up to one-third report gastrointestinal symptoms during the acute phase, and a meaningful minority go on to meet criteria for PI-IBS months later.
Symptoms of PI-IBS
The hallmark of PI-IBS is the timing. Bowel symptoms begin after, and persist beyond, the initial infection.
Typical symptoms include:
- Cramping or diffuse abdominal pain that eases after a bowel movement
- Frequent loose stools, an urgent need to empty bowels, or, in some people, sudden swings between diarrhoea and constipation
- Bloating or a sensation of incomplete emptying
If you notice blood in your stool, significant weight loss, or symptoms waking you at night, these could indicate a more serious condition. For reassurance, it’s best to see your GP or a specialist.
Diagnosing and managing IBS
Although there is no verified test for IBS, it is usually diagnosed by discussing your symptoms. Tests can be organised to rule out other conditions, including scans or a bowel endoscopy.
There is a lot that can be done to help treat symptoms of IBS. Management of IBS varies from individual to individual, but typically includes dietary and behaviour modifications, probiotics and medications.
If you are experiencing symptoms of IBS, be it post-infectious or not, schedule an appointment with Mr Michael Stellakis. He has established a respected interest in IBS and sees many patients with this condition, helping them with management strategies and individualised treatments. Call 01926 492969 to arrange a consultation.
