What is post-infectious IBS?
Post-infectious IBS is a form of IBS that is caused by food poisoning and can include autoimmunity. Post-infectious IBS almost always has a diarrheal component with patients suffering from symptoms of IBS-D and IBS-M.
Post-infectious IBS can be detected by measuring scientifically validated biomarkers in blood.
How common is post-infectious IBS?
According to the CDC, 48 million new cases of food poisoning occur every year in the US. Research shows that 11% (1 in 9) of food poisoning cases lead to IBS. (Read more.) There may be more than 5 million new cases of post-infectious IBS a year in the US.
Over 60% of IBS-D cases could be post-infectious (caused from food poisoning). Post-infectious IBS rarely manifests as constipation-predominant (IBS-C).
What kind of bacteria cause food poisoning and post-infectious IBS?
The most common forms of bacteria that cause food poisoning are Shigella, Campylobacter, C. difficile, Salmonella, and E. coli.
Can parasites cause post-infectious IBS?
Giardia, a parasite, can lead to elevated anti-vinculin levels, causing IBS. The measurement of IBS biomarkers from IBS blood tests does not distinguish whether the cause is Giardia or bacteria.
Your healthcare provider would need to clinically assess whether an infection was parasitic.
How does post-infectious IBS develop?
All of the most common types of bacteria that cause food poisoning release a toxin known as CdtB when infecting the body. This prompts an immune response through the creation of an antibody, anti-CdtB. Elevated anti-CdtB levels indicate IBS.
Additionally, CdtB looks similar to vinculin, a naturally occurring protein required for healthy gut function. Because of this similarity in structure, your body is tricked into producing anti-vinculin antibodies which attack and damage the gut, leading to the development of autoimmunity and worsening of IBS symptoms.
Elevated levels of anti-CdtB and/or anti-vinculin indicate IBS with up to 100% certainty.
What are the symptoms of post-infectious IBS?
Post-infectious IBS manifests as IBS-D (diarrhea-predominant) or IBS-M (mixed constipation and diarrhea). Symptoms of post-infectious IBS are the symptoms of IBS-D and IBS-M and include diarrhea or alternating diarrhea and constipation, abdominal pain and cramping, bloating, excess gas, bowel urgency, and unpredictability.