At some point in our lives most of us have been hit with an unpleasant gastro bug or food poisoning. The formal name for this is gastroenteritis (meaning stomach/intestinal infection) and is often caused by parasites (tiny bugs living in the gut). For ease of reading, I will simply refer to this throughout the article as gastro bugs. Growing research is showing there may be a link between gastro bugs (particularly those caused by parasites) and developing IBS.
In Australia the 2 most common intestinal parasites are known as B.hominis and D.fragilis. The gastro bugs caused by these parasites share similar symptoms to IBS. A few of these similar symptoms include stomach pain, diarrhoea, nausea, constipation, gas and bloating. Some studies have found both these parasites to be common in IBS sufferers, particularly B.Hominis. Because of their similar symptoms, it is possible for patients with parasite infections to be misdiagnosed with IBS. Often those with parasite infections will have no symptoms, and are simply ‘carriers’ of the parasite infection.
There is also the chance that the presence of these parasites may worsen IBS symptoms in some individuals. Don’t let this cause any freak outs or self-diagnosis though! If you have any concerns, chat with your doctor – not google!
Gastro bugs and IBS
Several studies have shown gastro bugs, caused by both a virus and bacteria/parasites, appear to increase the risk of developing IBS. This risk of developing IBS appears to be higher for parasitic/bacterial gastro bugs, rather than viral. The risk of developing IBS is thought to be 4-6 times higher after experiencing an episode of gastro. This is sometimes referred to as post-infectious IBS (IBS-PI). It seems there are certain people who are more likely to develop IBS-PI after a gastro bug. This includes those who experienced more severe cases of gastro, women and those with depression and/or anxiety.
So you have a parasite… what now?
The most common treatment for individuals with parasites is antibiotics, with metronidazole (antibiotic) usually being the first choice. Whilst antibiotics may be successful in some cases, it often isn’t an effective parasite treatment method. It seems that combination treatments are more effective for treating parasites, using 2-3 different anti-parasite medications. However, this also is often ineffective as many parasites can be very resistant to treatment in some individuals. Many people will later respond positively to treatment after it is re-trialled, but some will remain resistant.
As you can see, parasite-infections can be very difficult to manage. This is why it is important to work with a GP and/or gastroenterologist who specialises in parasites, to work out a treatment plan that works best for you.
Why might an episode of gastro increase risk of IBS?
Gastro bugs caused by bacterial/parasitic infection will upset the happy balance of gut bacteria. One of the proposed factors involved in developing IBS is a disruption in gut bacteria. This impact on gut bacteria offers one explanation as to why some gastro bugs may increase the risk of developing IBS. The use of certain probiotics may therefore be effective in treating some IBS-PI sufferers.
Further research will help better understand the possible relationship between gastro/parasites and IBS. At this stage, it is providing an interesting platform for exploring how some parasites may contribute to the development and symptoms of IBS.
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