Our new “about” site went live last week about Irritable bowel syndrome (IBS). IBS is one disorder in a spectrum of common functional gastrointestinal disorders.

The observation that the onset of IBS symptoms can be precipitated by gastrointestinal infection dates to the 1950s. Different studies have shown that 7-31% of individuals who have experienced an episode of infectious gastroenteritis, whether bacterial or viral, may develop symptoms of IBS.

One recent meta-analysis (a study that combines results from previously published research studies and analyzes the larger number) of 8 studies published between 1950 and 2005 found a positive association between gastrointestinal infection and the onset of IBS in 6 of the studies. In this meta-analysis alone, the average occurrence of post-infectious IBS was 9.8%, compared to 1.2% in the control group. This equates to a sevenfold increase in the odds of developing IBS after gastrointestinal infection.

There appear to be several risk factors associated with the development of post-infectious IBS, including female sex, severity and duration of the acute infectious illness, whether the person suffered from bloody stools, and psychological profile. As with non-post-infectious IBS, the precise mechanism that produces the symptoms is not specifically known. The pathogens known to precipitate post-infectious IBS symptoms include specifically, though not necessarily exclusively, Enterotoxigenic E. coli strains, Shiga toxin-producing E. coli strains (including E. coli O157:H7), Campylobacter, Shigella, and Salmonella.