Irritable Bowel Syndrome is a diagnosis of exclusion, which means that doctors diagnose it after eliminating all the other possibilities. The causes of IBS are still largely unknown, but preliminary research points to different genetic, hormonal & dietary factors that may play a role. Read on to learn the details about each one.<\/p>\n
The NIH estimates that as many as 20% of Americans may experience signs of IBS, but doctors still don\u2019t know the exact causes behind this syndrome (R<\/a>).<\/p>\n As you will see, IBS is a complex disease and there are many potential variables in the web of causes.<\/p>\n There are two main types of IBS – one that involves Diarrhea (IBS-D) and one that involves Constipation (IBS-C).<\/p>\n Food goes from stomach -> small intestine -> large intestine.<\/p>\n The large intestine is loaded with bacteria, but the rest of the gastrointestinal tract has relatively few bacteria under normal conditions. When a person has bacteria in the small intestine, unabsorbed carbohydrates are fermented there, producing significant amounts of gas.<\/p>\n This can cause cramping and burning because the gas stretches the small intestine. The gas can also push the intestinal content rapidly toward your large intestine to cause diarrhea. Bacteria generally ferment in the small intestines when gut \u2018flow’ (motility\/peristalsis) is slowed down in this area [R<\/a>, R<\/a>].<\/p>\n When people have diarrhea, it usually means the flow is quickened in the large intestine.<\/p>\n Gut pain comes from the neurons in the gut being \u2018hypersensitive\u2019. When the intestines expand, this is sensed by the neurons in the gut. If neurons are hypersensitive, this distension will feel uncomfortable or hurt.<\/p>\n This post is mainly about IBS, but other gut problems may stem from the same causes.<\/p>\n None of the below factors are established causes of IBS. According to preliminary research, they may play a role in this complex syndrome, but the evidence is inconclusive. If you recognize one or more of these factors in your case, it doesn\u2019t mean you have IBS. If you\u2019re experiencing digestive issues, work with your doctor to get adequate diagnosis and treatment.<\/i><\/p>\n Chronic stress response activation (HPA) is believed to be a contributing factor of anxiety disorders, bipolar, insomnia, PTSD, borderline personality, ADHD, major depression, burnout, chronic fatigue syndrome, fibromyalgia, IBS, alcoholism, and other diseases (R<\/a>).<\/p>\n Chronic stress is probably the most common and significant cause of gut flow (motility) changes. Indeed, increased activation of the stress pathway (HPA axis<\/a>) is associated with IBS (R<\/a>).<\/p>\n The effects of stress on the gut mostly have to do with the effects of Corticotropin-Releasing Hormone<\/a> (CRH), which is released from the hypothalamus<\/a> when stressed (R<\/a>).<\/p>\n CRH may play a role in IBS by increasing the flow or motor speed in the colon and decreasing it in the small intestine. When the flow is decreased in the small intestine, bad bacteria overgrow by feeding on carbs and produce gas (R<\/a>).<\/p>\n This fermentation in the small intestine can increase methane-producing bacteria from carbs, which produces methane gas (R<\/a>, R<\/a>).<\/p>\n People who get IBS are more susceptible to gut dysfunction when CRH is released. In IBS, there are increased HPA axis responses to stressors such as meals, hormones and mental stress compared to controls (R<\/a>, R<\/a>).<\/p>\n Therefore, stress is more harmful to people with IBS with regard to gut function.<\/p>\n CRH also causes the gut to be \u2018hypersensitive\u2019 and experience pain more. When given a drug that blocks CRH, some patients experienced pain relief (R<\/a>).<\/p>\n CRH may also play a role by:<\/p>\n Stress will also cause the release of various neurotransmitters (catecholamines), which decreases intestinal flow (R<\/a>).<\/p>\n Chronic stress or frequent activation of the HPA axis can cause oxidative stress<\/a> as well (R<\/a>).<\/p>\n Check out the posts on why stress is bad<\/a> and all of the triggers of stress response<\/a> for more details.<\/p>\n Adrenaline and noradrenaline<\/a>, through ADRA2A receptors, may inhibit gut flow (R<\/a>).<\/p>\n In addition, they cause a short-lived increase in blood pressure, but a long term decrease in blood pressure. They also cause sedation and thicker blood (platelet aggregation) (R<\/a>).<\/p>\n These can be common symptoms in people with IBS-C.<\/p>\n In some sense, IBS may be considered IBD-lite, which means it\u2019s like IBD<\/a> (Crohn’s, colitis), but with lower levels of inflammation. Patients with IBD experience IBS-like symptoms when their IBD cools down (R<\/a>).<\/p>\n A three-year study found that patients diagnosed with IBS were 16.3 times more likely to be diagnosed with IBD during the study period (R<\/a>).<\/p>\n The risk of developing IBS increases sixfold after acute gut infection. After salmonella, the risk can increase by 8X. This may be because infections cause inflammation and oxidative stress<\/a> (R<\/a>, R<\/a>).<\/p>\n Inflammation can affect the gut in many ways. One way is by activating our stress response\/HPA axis (R<\/a>).<\/p>\n People with IBS may have immune reactions to dietary proteins. In one study, food elimination based on IgG antibodies resulted in a significant decrease in symptoms of IBS (R<\/a>).<\/p>\n Mast cells may increase in intestinal mucosa in patients with IBS, especially by intestinal nerves. According to limited research, they can directly influence gut flow and result in an increase in abdominal pain and discomfort (R<\/a>).<\/p>\n There\u2019s evidence that anti-inflammatory drugs such as Mesalazine help treat IBS. Mesalazine helps to normalize the gut flora and reduce gut permeability (R<\/a>).<\/p>\n A wide variety of inflammation types can cause IBS. There\u2019s no one cytokine that\u2019s dominant.<\/p>\n According to some authors, people with IBS are more like to have:<\/p>\n If you click on the linked articles, you\u2019ll see how each parameter may impact inflammation and get some inflammation-lowering tips.<\/p>\n In some people with IBS, markers of oxidative stress were significantly higher – specifically, blood levels of xanthine oxidase (XO), adenosine deaminase<\/a> (AD), malondialdehyde (MDA) and nitric oxide (NO).<\/p>\n The enzymes that break down oxidants were significantly lower (Superoxide dismutase<\/a> (SOD<\/a>), Catalase<\/a> (CAT), and Glutathione peroxidase (GPx) (R<\/a>).<\/p>\nPotential Contributing Factors<\/span><\/h2>\n
1) Stress<\/b><\/span><\/h3>\n
CRH<\/b><\/h4>\n
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Adrenaline<\/b><\/h4>\n
2) Inflammation<\/b><\/span><\/h3>\n
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3) Oxidative Stress<\/b><\/span><\/h3>\n