A blog about IBS
IBS is often seen with IC…so I did a little research on some of the literature on IBS…more to come!
I encounter more and more people afflicted with IBS, and this includes children. When the pathophysiology of IBS was first considered in the 1950s and 1960s, the symptoms were largely attributed to psychiatric illness (Lacy, Chey, & Lembo, 2015). It wasn’t until the 1990s when the concept of the brain-gut axis gained popularity. Recent literature attributes the pathogenesis to genetics, the microbiome, immune activation and leaky gut (Lacy et al., 2015).
IBS can be evaluated using the DIGIN model since each aspect of the DIGIN model has a level of influence on IBS pathophysiology. Digestion / absorption of nutrients (D), intestinal permeability (I), Gut microflora (G), Immune dysfunction/inflammation (I) and enteric nervous system (N) can all be considered when evaluating IBS (Rakel, 2018). Interestingly, a “biopsychosocial model” has been proposed to account for the influence of interactions between the brain and the gut (Lacy et al., 2015). These include factors that may occur early in life such as impaired family dynamics, acute GI infections and the use/overuse of antibiotics. “These factors may predispose individuals to the development of abnormalities in enteric nerve dysfunction motility, visceral sensation, and brain-gut interactions, as well as mental health disorders” (Lacy et al., 2015).
Interestingly, the triggers encountered later in life is what is thought to exacerbate symptoms in patients who had underlying abnormalities such as motility, function and sensation. Food and stress appear to be significant triggers for many of the symptoms of IBS. Alterations in the gut microbiome have been found in IBS patients, including diversity ratios and distribution (Lacy et al., 2015). In addition, there is a condition known as post-infectious IBS which occurs after a GI infection (such as H. pylori) (Lacy et al., 2015). According to Lacy et. al, when IBS develops after an infection, symptoms will resolve in approximately two thirds of patients in 5 to 6 years. Multiple studies have shown an association between IBS and small intestinal bacterial overgrowth (SIBO) which supports the hypothesis that IBS consists of abnormalities in the microbiome. In fact the dysbiosis can occur in both the colon and small intestine. For example in the cases of IBS-D, loss of bacterial diversity is demonstrated with significantly higher levels of enterobacteriaceae and lower levels of fecalibacterium (Rakel, 2018). In IBS-C, lower levels of lactate-utilizing, hydrogen-consuming, methane-generating, acetate-generating organisms are seen.
Comorbid psychiatric condition such as anxiety, mood or panic disorder is often seen in IBS (Craig & Quigley, 2011). Patients often have elevated levels of cortisol and serotonin, which are associated with some of the symptoms such as altered gastric emptying, increased bowel contractions, faster bowel transit time and altered pain perception (Rakel, 2018) Recently probiotics have been trialed therapeutically with the aims to alter gut microflora. Probiotics appear to decrease fermentation, improve competition among commensal and pathogenic bacteria, and can stimulate the immune system (Rakel, 2018). The best-studied probiotic to date is b. infantis, which in 2 large, placebo-controlled trials that improved abdominal symptoms, including bloating and bowel function (Lembo, 2015.) L. plantaram/ B. breve are also probiotic combinations that also used, and the probiotic VSL #3 (Rakel, 2018). I recently gave my mother a probiotic blend aimed to help her with IBS (along with an elimination diet of course), so hoping to see some positive benefits for her symptoms.
Craig, O. F., & Quigley, E. M. (2011). Current and emerging therapies for the management of functional gastrointestinal disorders. Ther Adv Chronic Dis, 2(2), 87-99. doi:10.1177/2040622310389507
Lacy, B. E., Chey, W. D., & Lembo, A. J. (2015). New and Emerging Treatment Options for Irritable Bowel Syndrome. Gastroenterol Hepatol (N Y), 11(4 Suppl 2), 1-19.
Rakel, D. (2018). Integrative Mecidine (Vol. 4): Elsevier Inc.