If you are a regular reader of this column, you are probably familiar by now with IBS or Irritable Bowel Syndrome. It is common, affecting 10 to 15 percent of the population worldwide. Up to 20 percent of Americans are living with it every day. Symptoms include chronic or intermittent abdominal pain, cramping, bloating, gas, constipation, diarrhea, or a mixture of both, and can severely affect quality of life. While there are many theories about what causes IBS — including problems with brain-gut interaction, stress, mental disorders, genetics, food intolerances or sensitivities, bacterial infections, or Small Intestinal Bacterial Overgrowth — it was not until very recently that the most common cause was found: food poisoning. Read on to find out more about this common cause, how it relates to SIBO and the MMC (Migrating Motor Complex), testing that is now available, and why this is all important.

After many years (or decades) of not knowing the cause of IBS, we now know that many cases — but certainly not all — are actually caused by food poisoning, thanks to the gastroenterologist Dr. Mark Pimentel and his research team at Cedars-Sinai in Los Angeles. Dr. Pimentel is a leading expert in the field and is very active in research on IBS, SIBO, and gastrointestinal motility. He and his team discovered through their research studies that 60 to 70 percent of IBS-D (diarrhea type) and 20 to 25 percent of IBS-C (constipation-type) is caused by food poisoning. The official term is Post Infectious IBS (PI-IBS). Note: you do not need to recall a case of food poisoning to have had it. While diarrhea is often the most common symptom, though counterintuitive, constipation can sometimes be predominant, but is less common. Of course, not everyone who gets food poisoning gets IBS. (Only about 10 percent do.) In addition, a recent meta-analysis found that 38 percent of IBS individuals have Small Intestinal Bacterial Overgrowth. (Please see my previous articles for more on SIBO.) Interestingly, the most common SIBO (called Primary) is caused by food poisoning. This begs the question whether PI-IBS and Primary SIBO are actually the same thing.

There are now several labs that offer PI-IBS testing. They test for two antibodies: anti-cdtb antibodies and anti-vinculin antibodies. Cdtb is a toxin produced by all food poisoning bacteria, including campylobacter jejuni (the number-one cause of food poisoning), shigella, salmonella, some pathogenic strains of e. coli. A positive cdtb antibody test indicates that you had a case of food poisoning in the past in which your immune system mounted an attack. It does not necessarily indicate PI-IBS. However, a positive anti vinculin antibody does indicate PI-IBS. It means your body has an autoimmune reaction to vinculin, a protein within the small intestinal nerve cells. Your immune system mistakenly thinks vinculin is the food poisoning toxin and attacks it. The end result is damage to the Migrating Motor Complex (MMC). The MMC is a rhythmic cleaning action that sweeps down the digestive tract, starting in the stomach and moving down the intestines. It sweeps down cellular debris and microorganisms, and only happens in the fasted state, about 1.5 to 2 hours after finishing a meal. A damaged MMC can happen for many other reasons as well, but when it does happen, it predisposes one to getting SIBO. As food stagnates in the intestines, microbes have a longer chance to feast on food and multiply in the small intestine where they do not belong.

This is all important because it proves that IBS is a real disease with real markers; it is not just in your head. It can be very validating for those who have been suffering for a long time without answers. Patients also will get treatment much faster. It also saves on health care costs (an average of $800 per patient). In addition, having a diagnosis is important because those who have one are at higher risk of food poisoning in the future; smaller amounts of pathogenic bacteria are more likely to cause poisoning in those with slowed motility. Unfortunately, repeated cases of food poisoning can have an additive effect over time, increasing antibodies, worsening symptoms, and making management more difficult. This is especially important for those who eat out a lot or travel to places where hygiene may be an issue. In these cases, extra precautions when eating need to be taken. Some management options include prokinetics to support the MMC (both pharmacological or over the counter supplements); treating the SIBO and preventing relapses; providing digestive support; dietary modifications; working on vagal nerve tone; stress management; and being careful around food hygiene.

The field of digestive health is an exciting place to be right now. We now know a lot more than we did just a few years ago. Experts like Dr. Pimentel continue to do research on this topic and more will be learned. More information means less suffering as more individuals with PI-IBS/SIBO get the help that they deserve.

The information provided in this article is intended for general use only and is not to be used in place of medical advice from a licensed health professional.