We are living in challenging times, and stress affects patients in strikingly different ways—particularly those living with underlying conditions. Patients with irritable bowel syndrome (IBS) may be experiencing spikes in symptoms during the COVID-19 pandemic. IBS is a complex syndrome with many underlying subtypes.1 There are many possible underlying causes that can cause a diagnosis of IBS, including bile acid dysfunctions, infection, food intolerance, and more.2 In one study with over 3,000 participants diagnosed with IBS, more than half reported that their symptoms were “very bothersome.”3 A number of potential therapeutic options may help these patients, depending on their initial presentation and the underlying cause of their IBS. More effective, individualized treatment plans can be developed based on IBS type, acid balance, and motility.
Research is still uncovering all of the causes of and triggers for irritable bowel syndrome (IBS), many of which are lifestyle-related. As the underlying causes of IBS continue to be elucidated, targeted treatment that addresses each patient’s cause or subtype will likely lead to the best outcomes.
Selected Factors to Consider
There are many factors that may contribute to the development of IBS and continuing dysfunction. What follows is a small sampling of factors from the recent research for which the evidence is developing but fairly strong.
Bile acids (BA) have a significant effect on gut motility, sensory and secretory functions, intestinal permeability, and inflammatory response regulation. In one study, over a quarter of patients with IBS-D had BA malabsorption.4 Even in IBS patients without overt bile acid malabsorption, bile acids affect colonic transit time and fecal weight, strengthening the hypothesis that bile acids play an important role in IBS symptomotology.5 In one study, a 75SeHCAT scan found abnormal (<10%) BA levels in IBS patients. They also experienced more frequent stools, a faster colonic transit time, and rectal hyposensitivity.6 Treatments that alter bile acid production (like colestipol) also alter colonic transit time and fecal weight.5 Colestipol also improved severity symptom scores, providing adequate relief of IBS symptoms.6
The malabsorption of BA could potentially predispose IBS patients to diarrhea, and both are being examined as a cause for IBS and even a potential treatment path.7 In one study, patients with IBS-C (constipation-predominant IBS) had high levels of serum and amino-conjugated BA levels but decreased BA deconjugation activity compared to healthy volunteers.8 IBS-D (diarrhea-predominant IBS) patients had increased fecal primary, sera primary, and amino-conjugated BA levels but decreased BA deconjugation activity.8 Serum and fecal primary BA was associated with abdominal pain in all IBS patients.8
Low vitamin D status has been associated with some gastrointestinal disorders, including IBS.9 In a 2019 study, lower serum concentrations of D3 were associated with higher severity of abdominal pain and distension, flatulence, and overall GI symptoms.9 A 2020 randomized clinical trial of 74 patients suggests that vitamin D3 supplementation can modulate the serum level of corticotropin-releasing hormone and interleukin-6 (which increase with stress and gut inflammation).10 Patients with IBS-D treated with D3 reported improvements in symptoms.10 Vitamin D has helped symptoms in a range of studies,11-13 and likely effects would be stronger if each study had tested for deficiency and dosed based on response to supplementation.
In a 2018 review article, the observational studies reported that a substantial proportion of the IBS population was vitamin D deficient. Two intervention studies reported improvement in IBS symptom severity scores and quality of life with vitamin D supplementation. However, there are limited data around the role of vitamin D in IBS.14
A variety of lifestyle interventions to restore a healthy microbiome and reduce gut permeability are known to be crucial for treating IBS.15-17
In IBS, the gut-brain connection is a little-realized factor in symptom severity. Research suggests that negative emotions, such as anxiety, play a major role in gastrointestinal (GI) functioning due to the bidirectional communication between gut and brain—the gut-brain axis.18 Gut-brain dysfunction leading to depression and anxiety has been found in some IBS patients.19 While the connection is bi-directional, researchers are still studying the question of causality: does anxiety cause GI dysfunction or does GI dysfunction lead to anxiety? Or is there another factor that causes them both?
Some literature implies that mood disorders “cause” gastrointestinal symptoms, but epidemiological data provide strong evidence that in subsets of cases, GI symptoms arise first and mood disorders occur later.19 In other patients, the reverse appears to happen.19 However, one 2016 meta-analysis suggests that patients who had anxiety or depression were twice as likely to develop new-onset IBS.20 Polish researchers found that biochemical markers of stress and anxiety (activation of the autonomic nervous system and an increase in cortisol levels and proinflammatory cytokines) weaken gut tight junctions, with a resulting increase of bacterial translocation.21 The way in which emotions and feelings are related to gut homeostasis continues to be studied.
A treatment plan addressing both gut and brain has proven successful in managing stress and relieving IBS symptoms in some patients.22,23 Although evidence is limited, psychological therapies, including cognitive behavioral therapy, relaxation therapy, and hypnotherapy, may be effective treatments for IBS, as cited in a 2019 systematic review and meta-analysis.24 A 2018 systematic review included mindfulness-based stress reduction, guided affective imagery, and emotional awareness training as potential beneficial interventions.25 The authors of both reviews note that the research is promising, but the interventions mentioned are in need of further study. It’s interesting to note that a 2017 analysis of placebo response in studies with psychological interventions for IBS patients found that the effect was similar to other types of interventions like pharmaceuticals.26
Some researchers have begun to study yoga as a potential intervention for IBS patients as well. In a small 2018 randomized clinical trial, yoga performed as well as FODMAPs in statistically improving IBS symptoms.27 A 2019 review stated that, “evidence from randomized controlled trials identified yoga as more effective [for IBS patients] compared to pharmacological treatment and equally effective as dietary interventions or moderate-intensity walking.”28 Improvements were seen in both physical health (IBS symptom severity, gastric motility, autonomic and somatic symptom scores, and physical functioning) and mental health outcomes (depression, anxiety, gastrointestinal-specific anxiety, and quality of life).28 More research on the underlying mechanisms of yoga as an intervention for IBS patients is warranted.
There are many other factors that can contribute to or mediate IBS symptoms. Add new Functional Medicine tools to your clinical toolkit that can help you recognize and treat the most important antecedents and triggers of gastrointestinal dysfunction. For more information:
- Grad S, Dumitrascu DL. Irritable bowel syndrome subtypes: new names for old medical conditions. Dig Dis. 2020;38(2):122-127. doi:1159/000505287
- Hadjivasilis A, Tsioutis C, Michalinos A, Ntourakis D, Christodoulou DK, Agouridis AP. New insights into irritable bowel syndrome: from pathophysiology to treatment. Ann Gastroenterol. 2019;32(6):554-564. doi:20524/aog.2019.0428
- Ballou S, McMahon C, Lee HN, et al. Effects of irritable bowel syndrome on daily activities vary among subtypes based on results from the IBS in America survey. Clin Gastroenterol Hepatol. 2019;17(12):2471-2478.e3. doi:1016/j.cgh.2019.08.016
- Slattery SA, Niaz O, Aziz Q, Ford AC, Farmer AD. Systematic review with meta-analysis: the prevalence of bile acid malabsorption in the irritable bowel syndrome with diarrhoea. Aliment Pharmacol Ther. 2015;42(1):3-11. doi:1111/apt.13227
- Peleman C, Camilleri M, Busciglio I, Burton D, Donato L, Zinsmeister AR. Colonic transit and bile acid synthesis or excretion in patients with irritable bowel syndrome–diarrhea without bile acid malabsorption. Clin Gastroenterol Hepatol. 2017;15(5):720-727.e1. doi:1016/j.cgh.2016.11.012
- Bajor A, Törnblom H, Rudling M, Ung KA, Simrén M. Increased colonic bile acid exposure: a relevant factor for symptoms and treatment in IBS. Gut. 2015;64(1):84-92. doi:1136/gutjnl-2013-305965
- Panek-Jeziorna M, Mulak A. The role of bile acids in the pathogenesis of bowel diseases. Postepy Hig Med Dosw (Online). 2017;71(1):737-746. doi:5604/01.3001.0010.3852
- Dior M, Delagrèverie H, Duboc H, et al. Interplay between bile acid metabolism and microbiota in irritable bowel syndrome. Neurogastroenterol Motil. 2016;28(9):1330-1340. doi:1111/nmo.12829
- Abbasnezhad A, Amani R, Hasanvand A, et al. Association of serum vitamin D concentration with clinical symptoms and quality of life in patients with irritable bowel syndrome. J Am Coll Nutr. 2019;38(4):327-333. doi:1080/07315724.2018.1510349
- Khalighi Sikaroudi M, Mokhtare M, Janani L, et al. Vitamin D3 supplementation in diarrhea-predominant irritable bowel syndrome patients: the effects on symptoms improvement, serum corticotropin-releasing hormone, and interleukin-6 – a randomized clinical trial. Complement Med Res. Published online March 23, 2020. doi:1159/000506149
- El Amrousy D, Hassan S, El Ashry H, Yousef M, Hodeib H. Vitamin D supplementation in adolescents with irritable bowel syndrome: is it useful? A randomized controlled trial. Saudi J Gastroenterol. 2018;24(2):109-114. doi:4103/sjg.SJG_438_17
- Jalili M, Vahedi H, Poustchi H, Hekmatdoost A. Effects of vitamin D supplementation in patients with irritable bowel syndrome: a randomized, double-blind, placebo-controlled clinical trial. Int J Prev Med. 2019;10:16. doi:4103/ijpvm.IJPVM_512_17
- Tazzyman S, Richards N, Trueman AR, et al. Vitamin D associates with improved quality of life in participants with irritable bowel syndrome: outcomes from a pilot trial. BMJ Open Gastroenterol. 2015;2(1):e000052. doi:1136/bmjgast-2015-000052
- Williams CE, Williams EA, Corfe BM. Vitamin D status in irritable bowel syndrome and the impact of supplementation on symptoms: what we do know and what do we need to know? Eur J Clin Nutr. 2018;72(10):1358-1363. doi:1038/s41430-017-0064-z
- Leventogiannis K, Gkolfakis P, Spithakis G, et al. Effect of a preparation of four probiotics on symptoms of patients with irritable bowel syndrome: association with intestinal bacterial overgrowth. Probiotics Antimicrob Proteins. 2019;11(2):627-634. doi:1007/s12602-018-9401-3
- Francavilla R, Piccolo M, Francavilla A, et al. Clinical and microbiological effect of a multispecies probiotic supplementation in celiac patients with persistent IBS-type symptoms: a randomized, double-blind, placebo-controlled, multicenter trial. J Clin Gastroenterol. 2019;53(3):e117-e125. doi:1097/MCG.0000000000001023
- Pusceddu MM, Murray K, Gareau MG. Targeting the microbiota, from irritable bowel syndrome to mood disorders: focus on probiotics and prebiotics. Curr Pathobiol Rep. 2018;6(1):1-13. doi:1007/s40139-018-0160-3
- Pellissier S, Bonaz B. The place of stress and emotions in the irritable bowel syndrome. Vitam Horm. 2017;103:327-354. doi:1016/bs.vh.2016.09.005
- Holtmann G, Shah A, Morrison M. Pathophysiology of functional gastrointestinal disorders: a holistic overview. Dig Dis. 2017;35(Suppl 1):5-13. doi:1159/000485409
- Sibelli A, Chalder T, Everitt H, Workman P, Windgassen S, Moss-Morris R. A systematic review with meta-analysis of the role of anxiety and depression in irritable bowel syndrome onset. Psychol Med. 2016;46(15):3065-3080. doi:1017/S0033291716001987
- Brzozowski B, Mazur-Bialy A, Pajdo R, et al. Mechanisms by which stress affects the experimental and clinical inflammatory bowel disease (IBD): role of brain-gut axis. Curr Neuropharmacol. 2016;14(8):892-900. doi:2174/1570159X14666160404124127
- Edebol-Carlman H, Ljótsson B, Linton SJ, et al. Face-to-face cognitive-behavioral therapy for irritable bowel syndrome: the effects on gastrointestinal and psychiatric symptoms. Gastroenterol Res Pract. 2017;2017:8915872. doi:1155/2017/8915872
- Shah K, Ramos-Garcia M, Bhavsar J, Lehrer P. Mind-body treatments of irritable bowel syndrome symptoms: an updated meta-analysis. Behav Res Ther. 2020;128:103462. doi:1016/j.brat.2019.103462
- Ford AC, Lacy BE, Harris LA, Quigley EMM, Moayyedi P. Effect of antidepressants and psychological therapies in irritable bowel syndrome: an updated systematic review and meta-analysis. Am J Gastroenterol. 2019;114(1):21-39. doi:1038/s41395-018-0222-5
- Thakur ER, Shapiro J, Chan J, et al. A systematic review of the effectiveness of psychological treatments for IBS in gastroenterology settings: promising but in need of further study. Dig Dis Sci. 2018;63(9):2189-2201. doi:1007/s10620-018-5095-3
- Flik CE, Bakker L, Laan W, van Rood YR, Smout AJ, de Wit NJ. Systematic review: the placebo effect of psychological interventions in the treatment of irritable bowel syndrome. World J Gastroenterol. 2017;23(12):2223-2233. doi:3748/wjg.v23.i12.2223
- Schumann D, Langhorst J, Dobos G, Cramer H. Randomized clinical trial: yoga vs a low-FODMAP diet in patients with irritable bowel syndrome. Aliment Pharmacol Ther. 2018;47(2):203-211. doi:1111/apt.14400
- D’Silva A, MacQueen G, Nasser Y, Taylor LM, Vallance JK, Raman M. Yoga as therapy for irritable bowel syndrome. Dig Dis Sci. Published online December 12, 2019. doi:1007/s10620-019-05989-6