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REVIEW ARTICLE

Complementary and Alternative Medicine for Functional Gastrointestinal Disorders

Deutsch, Jill K. MD1; Levitt, Joshua ND2; Hass, David J. MD, FACG1,3

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The American Journal of Gastroenterology: March 2020 - Volume 115 - Issue 3 - p 350-364
doi: 10.14309/ajg.0000000000000539
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Abstract

INTRODUCTION

Complementary and alternative medicine (CAM) is a unique group of medical practices and products neither taught widely in traditional medical schools nor generally available in US hospitals (1). More specifically, complementary medicine is used in conjunction with traditional medicine, alternative medicine is used in lieu of traditional medicine, and integrative medicine combines CAM modalities with traditional medicine practices (2). The overarching philosophy of CAM is based on a holistic approach wherein all disease results from disturbances on physical, psychological, social, and spiritual levels. Thus, CAM modalities are used to restore balance and to facilitate the body's own healing to improve troublesome symptoms (3).

The National Center for Complementary and Integrative Health divides CAM therapies into 2 major subgroups. The first is natural products, which constitute substances within our environment that are used to strengthen and heal the human body such as herbs, vitamins, minerals, and probiotics. These are commonly sold as dietary supplements. The second is mind-body medicine which includes procedures and techniques administered by a practitioner or practiced independently by the patient such as yoga, hypnosis, meditation, biofeedback, and relaxation practices. Other mind-body practices such as manipulation and movement of one or more parts of the body to achieve healing include acupuncture, chiropractic manipulation, Pilates, Qi Gong, and Tai Chi. Many of the mind-body medicine practices are outlined in Table 1.

Table 1
Table 1:
Glossary of mind-body medicine terms relating to complementary and alternative medicine

There are several well-described alternative medical systems which do not traditionally fall into either of these subgroups including ayurveda, reiki, traditional Chinese medicine (TCM), homeopathy, anthroposophic medicine, and naturopathic medicine. Ayurvedic medicine is a traditional Indian practice based on the premise of balance; it is a comprehensive medical discipline aimed at integrating mind, body, and spirit to achieve contentment, prevention of disease, and good health. Reiki uses the power of touch to channel energy into a patient to activate natural healing processes and restore physical well-being. TCM has a heritage more than 2000 years old and attempts to bring a patient into balance through practices that affect the opposing forces of yin and yang. Homeopathy treats disease by administering small doses of a diluted substance that when otherwise administered in undiluted forms would elicit symptoms of the disease. Anthroposophic medicine is a form of complementary medicine that adds spiritual insight into disease diagnosis and healing; it is applied by conventionally trained medical doctors where there is a strong belief that human beings, nature, and the cosmos are interrelated (4). Within this discipline, homeopathic and herbal remedies, home care, nursing, artistic therapies including music and art, hydrotherapy, eurythmy (movement), and massage, all have a role (5). Naturopathic medicine as defined by the American Association of Naturopathic Physicians is “a distinct healthcare profession emphasizing disease prevention and treatment through the use of methods and substances that encourage individuals' inherent self-healing process. The practice of naturopathic medicine includes modern and traditional, scientific, and empirical methods including but not limited to clinical and laboratory diagnostic testing, nutritional medicine, botanical medicine, physical medicine, and lifestyle and dietary counseling.” (6) The practice of naturopathic medicine in the United States requires specialized training including attending an accredited school and obtaining national licensure.

BACKGROUND

The prevalence of CAM therapies continues to increase both in national and international medical communities. In the 2012 National Health Interview Survey (NHIS) from a sample of 13,505 respondents, 42% of the individuals said that they had used a CAM therapy within the past year (7). An updated NHIS survey in 2017 revealed an increase in the use of yoga, meditation, and chiropractors (8). A 2018 systematic review published by Gan et al. (9) reported the prevalence of CAM therapies for gastrointestinal (GI) disorders to range from 23.6% to 44%, predominantly used by women with a higher income and level of education. Larussa et al. (10) also published on a statistically significant association between CAM use and higher body mass index (P = 0.004). Estimated annual expenditures for CAM therapies are in excess of $30.2 billion (11) and have previously been reported to cost patients in excess of $200 per year (12). The prevalence of use of CAM therapies in gastroenterology outpatients in both a community and university setting has been reported at 44%–50% (13,14). The 2012 NHIS survey reported that at least 3% of those who had used CAM in the past year used it to address a GI condition, and over 80% of those people perceived it to be useful (7).

CAM therapies are attractive to patients for several reasons. First, they can provide patients with a sense of control over their own bodies and health. Second, they provide patients with therapeutic alternatives when conventional medical therapies have failed to alleviate symptoms or cure diseases. Last, CAM therapies are attractive to patients who feel dissatisfied with the ways their physicians understand and explain illnesses or complaints. The functional gastrointestinal disorders are particularly well suited to the use of CAM therapies, representing a significant portion of disorders where data show the most benefit.

This review is intended to provide information regarding the use of complementary and alternative therapies to gastroenterologists for some of the most common functional GI disorders. It is difficult to make recommendations for the use of any of these modalities in one particular subset of patients, rather this information should be used to guide patients who are seeking alternative or complementary strategies to treatment.

NAUSEA AND VOMITING

Nausea and vomiting have a wide array of etiologies ranging from acute disease processes such as viral gastroenteritis to subacute processes like pregnancy. Traditional agents with antiemetic properties often provide relief; however, in some patients who do not obtain adequate symptom relief, adjunctive CAM therapies can be useful. Some of the therapies cited in this section are also listed in Table 2.

Table 2
Table 2:
CAM therapies for nausea and vomiting

Natural products

Ginger (Zingiber officinale) is the most common herbal product used to relieve nausea and vomiting; its name is derived from the Sanskrit word for “horn,” which describes the twisted and gnarled shape of its roots. There are many proposed antiemetic mechanisms of action for ginger. Animal studies have demonstrated that one component of the herb, 6-gingerol, improves GI motility (15) and another component, galanolactone, is a 5-hydroxytryptamine HT3 antagonist similar to ondansetron (16). Dossett et al. (39) suggest both an anticholinergic and antiserotonergic component to ginger's antiemetic effects. In a systematic review of randomized controlled trials (RCTs) that evaluated the efficacy of ginger for nausea and vomiting, Ernst and Pittler demonstrated that in 2 of the studies, ginger was superior to placebo and equal in efficacy to metoclopramide for postoperative nausea and vomiting; however, in pooled analysis, there was a nonsignificant difference between ginger and placebo groups (adjusted risk ratio for the incidence of postoperative nausea 0.052, 95% confidence interval [CI] [−0.082 to −0.186]; number needed to treat 19) (20). Although ginger is generally considered to be safe as a natural supplement, its potential adverse effects (AEs) must be taken into account. Ginger has been shown to inhibit platelet aggregation by inhibiting thromboxane synthase (17), thus increasing the risk of bleeding in patients already on antiplatelet therapy. In addition, ginger has been documented to be potentially mutagenic, raising concerns about its safety in pregnancy (18,19).

The vitamin pyridoxine (vitamin B6) is another CAM therapy commonly used to relieve nausea and vomiting, although nearly all studies published have shown an effect on nausea in pregnancy only (15,23,40).

Finally, cannabis is frequently used by patients, both in inhaled and ingested forms, to attenuate upper GI symptoms such as nausea and vomiting (41). There are no RCTs to date on the effect of cannabis on nausea and vomiting. One potential risk to regular or routine use of cannabis is the cannabinoid hyperemesis syndrome. Given that marijuana remains a federal schedule 1 controlled substance, providers cannot prescribe but rather can make “recommendations,” for its use.

Mind-body medicine

Acupuncture for the relief of nausea and vomiting has been well described; the P6 acupuncture point stimulated to achieve relief of these symptoms is termed neiguan, meaning “medial pass” and is located 2 1/2 to 3 finger-breadths above the proximal palmar crease on the volar aspect of the wrist in the midline (42). There have been more than 50 published trials on the stimulation of the P6 acupuncture point to relieve symptoms of nausea and vomiting. In a systematic review of nearly 30 publications, consistent results suggested that acupuncture is superior to placebo in ameliorating nausea and vomiting (postoperative, chemotherapy related, or secondary to pregnancy) (43); however, definitive conclusions of superiority could not be made (39). Although the data to support the use of acupuncture are impressive, there are numerous practitioners, a diverse patient population and various forms of acupuncture point stimulation. This should be considered if a gastroenterologist is to recommend this CAM therapy because each patient's regimen should be individualized to his or her specific symptoms. In addition, several AEs have been reported with the use of acupuncture related to improper needle sterilization, resulting in infections such as HBV, HCV, HIV, and bacterial endocarditis (25,26). In addition, needle placement and depth of insertion variability has resulted in solid and hollow organ perforation (25–27).

It is well established that the anxiety experienced during stressful situations can serve as a conditioning cue which leads to the physiologic reaction of nausea and vomiting. Relaxation therapy including progressive muscle relaxation can help alleviate a patient's anxiety surrounding symptoms of nausea and vomiting. Relaxation therapy often is used in conjunction or as an adjunct to standard antiemetic medications (36).

FUNCTIONAL DYSPEPSIA

Often dyspeptic symptoms tend to be short in duration and relatively mild; thus, many patients feel they can self-manage. However, large scale studies report a 10–30% prevalence of functional dyspepsia (FD) worldwide (44). CAM therapies are particularly appealing for these patients who do not want to be on long-term medication. Herbal therapy has been the mainstay of CAM treatments for FD; several herbal therapies are discussed in detail below and additional supplements are detailed in Table 3.

Table 3-a
Table 3-a:
CAM therapies for functional dyspepsia (FD)
Table 3-b
Table 3-b:
CAM therapies for functional dyspepsia (FD)
Table 3-c
Table 3-c:
CAM therapies for functional dyspepsia (FD)

Natural products

Peppermint (Mentha piperita) and caraway (Carum carvi) are the natural CAM therapies that have been studied most extensively in the treatment of FD. The proposed mechanism of action is thought to be related to the inhibition of smooth muscle contraction by direct blockade of smooth muscle calcium channels (54,55). In addition, an allosteric effect of menthol and peppermint oil on the 5-HT3 receptor has been proposed to explain its antiemetic properties (56). Finally, a spasmolytic effect in the esophagus, distal stomach, and duodenal bulb has been proposed when orally administered in patients with FD (57). Several placebo-controlled trials have compared fixed dose combinations of peppermint (180–270 mg daily) and caraway (100–150 mg daily). The overwhelming outcome of these studies demonstrates a statistically significant improvement in bloating and epigastric pain for the treatment groups over the placebo group (61,75). After 29 days of therapy, 96 outpatients reported that average intensity of pain was reduced by 2.60 ± 2.44 points (mean ± SD), or 40% reduction compared with a 1.46 ± 1.77 point (mean ± SD), or 22% reduction in the placebo group (P = 0.0003) (61). FDgard is a commercially available nonprescription formulation containing a fixed dose of L-menthol (20.75 mg) and caraway (25 mg) for the management of FD. More recently, Chey et al. (62) reported that in a group of 95 patients on usual treatment for FD at 24 hours, the group receiving duodenal release fixed dose caraway oil and L-menthol reported a statistically significant (P = 0.039) reduction in sensation of pressure, heaviness, and fullness measured by the global overall symptoms score (improved in the treatment group from 4.5 to 4 [−9.9%] compared with change in placebo group from 4.4 to 4.4 [0.1%]) with a trend toward improvement in epigastric pain symptoms (P = 0.074) where the global symptoms score improved in the treatment group from 4.4 to 3.8 (−14%) and in the placebo group from 4.4 to 4.2 (−6.9%). AEs with these supplements include diarrhea, nausea and vomiting, allergic contact dermatitis, urticaria, asthma exacerbation, and atrial fibrillation (58–60).

Deglycyrrhizinated licorice (Glycyrrhiza glabra) has been used for a number of years to enhance gastric mucus secretion and promote antiulcer properties (50); a number of in vitro and in vivo studies have shown efficacy and safety. One RCT published in 2010 studied the efficacy of deglycyrrhizinated licorice for the treatment of FD (50). Fifty patients were randomized to receive either Gutgard (glabridin [≥3.5% w/w], glabrol [≥0.5% w/w], eicosanyl caffeate [≥0.1% w/w], docosyl caffeate [≥0.1% w/w], glycyrrhizin [≤0.5% w/w], and total flavonoids [≥10% w/w]) 75 mg orally twice daily for 30 days or placebo. The total symptom score was obtained at 15 days and 30 days of treatment and was noted to be statistically significantly improved in the Gutgard group compared with placebo (change in the baseline global symptom score at day 15 of −11.32 ± 0.77 [mean ± SD] and at day 30 of −15.2 ± 0.71 [mean ± SD], P ≤ 0.05) (50). It should be noted that the licorice root is an inhibitor of 11β-hydroxysteroid dehydrogenase which can raise serum cortisol levels and, in some patients, can result in hypokalemia and hypertension. These parameters should, therefore, be routinely monitored in a patient using licorice for relief of FD symptoms.

STW-5 (Iberogast) is an herbal preparation composed of bitter candytuft (Iberis umbellata), chamomile (Matricaria chamomilla), peppermint (M. piperita), caraway (C. carvi), licorice root (G. glabra), lemon balm leaves (Melissa officinalis), celandine (Chelidonium majus), angelica root (Angelica archangelica), and milk thistle (Silybum marianum). Pilichiewicz's group proposed that the mechanism of STW-5 is related to gastric motility in a region-dependent manner including fundic relaxation and antral contraction (66). In addition, it has been proposed that the synergistic effects of the STW-5 herbs create a spasmolytic effect on acetylcholine-induced contractions (67). A double-blind noninferiority RCT comparing STW-5 with cisapride showed equal effectiveness for both medications to improve dyspepsia specific gastrointestinal symptom scores (79). Melzer et al. (72) reported that in a meta-analysis of 3 double-blind RCTs that STW-5, when administered in a dosage of 1 mL 3 times daily for 4 weeks was more effective than placebo to improve symptoms of epigastric pain and gastroesophageal reflux disease. At the end of the intervention, the most bothersome symptoms remained “severe” or “very severe” in 26% of patients in the placebo group but only in 7% of the patients in the STW-5 group resulting in a statistically significant difference of 19% (odds ratio 0.22, 95% CI [0.11–0.47], P < 0.001) (72). von Arnim et al. (73) reported that a significantly higher percentage of patients with FD who were prescribed STW-5 were free from symptoms (improvement in symptom score by 6.9 ± 4.8 [mean ± SD]) compared with the placebo group (improvement in symptom score by 5.9 ± 4.3 [mean ± SD], P < 0.05). STW-5 has been implicated in a single case report of hepatotoxicity resulting in liver transplantation (68); individual components of the preparation are also known to have potential toxicity including hepatotoxicity (52), increased bleeding, potentiation of sedatives and anxiolytics (69,70), and altered metabolism of drugs metabolized by CYP3A4 and uridine diphosphate-glucuronyltransferase (71).

Rikkunshito is a well-known Japanese Kampo (the Japanese study of TCM) treatment (similar to liu-jun-zi-tang [TJ-43]) composed of 8 constituents—licorice root (G. glabra), ginger rhizome (Z. officinale), Atractylodis laneae rhizoma, Zizyphi fructus, Aurantii nobilis pericarpium, Ginseng radix, Pinelliae tuber, and hoelen (Wolfiporia extensa). In animal models, the proposed mechanism of action is thought to be related to accelerated gastric emptying and increased plasma ghrelin concentration (45). Additional studies in vitro suggest that rikkunshito improved gastric threshold for first sensation of epigastric discomfort (63). A small study of 9 patients in Japan reported that rikkunshito significantly reduced epigastric fullness (P = 0.037) and perceived stress (P = 0.034) (65). Although symptomatic improvement of FD was reported in a multicenter RCT in Asia for the group receiving rikkunshito (42/125 [33.6%] patients receiving rikkunshito reported “extremely improved” or “improved” symptoms), this was not statistically significant when compared with the control group (29/122 [23.8%] patients reporting “extremely improved” or “improved” symptoms, P = 0.09) (64). No severe AEs were reported in any of the studies with rikkunshito (64).

Mind-body medicine

Acupuncture has been extensively studied for use in patients with FD, although data are of low quality and reports are contradictory regarding its benefit in FD. Pang et al. (76) published a meta-analysis of 16 RCTs in 2016 involving 1,436 participants who concluded that acupuncture for FD can alleviate postprandial fullness and early satiety; however, data from this study proved to be heterogenous and of low quality of evidence. Contradictory to this meta-analysis, an older Cochrane review published in 2014 of 7 RCTs including 542 patients concluded that manual and electroacupuncture is not known to be more effective than other treatments for patients with FD; this included 4 RCTs comparing medications such as cisapride, itopride, and domperidone as well as 3 RCTs comparing acupuncture with sham (77).

Hypnosis has also been shown to ameliorate symptoms and improve quality of life in patients with FD. A study by Chiarioni et al. (80) compared hypnosis with cisapride for gastric emptying and concluded that hypnosis was significantly more effective than cisapride in increasing gastric emptying in patients with FD (basal: 274 ± 16.6 [mean ± SD] minutes, cisapride: 227 ± 13.2 [mean ± SD] minutes, hypnosis: 150 ± 9.7 [mean ± SD] minutes, P < 0.005). The mean paired difference in the total emptying time in dyspeptic patients between cisapride and hypnosis was a decrease by 77 minutes (95% CI [57.9–96.1], P < 0.001) (80).

IRRITABLE BOWEL SYNDROME

Patients with irritable bowel syndrome (IBS) are often frustrated that laboratory, radiographic, and endoscopic examinations fail to reveal an “organic” source for their discomfort or abnormal bowel habits, and they subsequently use CAM therapies to ameliorate symptoms. There are several well-studied natural products and mind-body therapies that have shown effect for relief of IBS symptoms; these are outlined in Table 4. The most common targets for CAM therapies in IBS are relief of visceral hypersensitivity which is thought to mediate pain, as well as normalizing the frequency and consistency of individual bowel movements.

Table 4-a
Table 4-a:
CAM therapies for irritable bowel syndrome (IBS)
Table 4-b
Table 4-b:
CAM therapies for irritable bowel syndrome (IBS)
Table 4-c
Table 4-c:
CAM therapies for irritable bowel syndrome (IBS)

Natural products

Psyllium (Plantago isphaghula) is one of the most frequently prescribed supplements for patients suffering from IBS. Fiber acts as an osmotic bulking agent and decreases bowel transit time. There have been numerous low-quality studies published on the use of psyllium in IBS which generally support a modest improvement in stool frequency, consistency, and ease of passage (108–110). A systematic review evaluating 14 RCTs concluded that there was a significant benefit in global symptom improvement to using soluble fiber with a number needed to treat of 7 compared with wheat bran (risk ratio [RR] = 0.83, 95% CI [0.73–0.94] with an number needed to treat = 7; 95% CI [4–25]) (111). A European meta-analysis concluded similarly that soluble fiber improved assessment of symptoms (RR 1.49; 95% CI [1.09–2.03]) and abdominal pain (mean difference: −1.84, 95% CI [−2.72 to 0.97]), whereas insoluble fiber did not show benefit (82). Conflicting data have been reported regarding the effect when different primary outcomes are evaluated. Although there are few serious AEs reported with the use of psyllium, some patients have reported an allergic hypersensitivity and others who take certain medications such as lithium and carbamazepine (81) have reported impaired absorption. In those who are unable to tolerate psyllium, dietary supplements such as prunes have shown efficacy in improvement of constipation, but not overall symptom improvement in IBS; this is contrary to the dietary modification of a low-FODMAP diet (short chain carbohydrates that are incompletely absorbed in the small intestine including oligosaccharides, disaccharides, monosaccharides, and polyols) (112). These carbohydrates are proposed to worsen IBS symptoms by fermentation in the colon, thus producing gas and distension as well as by osmotic activity leading to increased water content within the intestinal lumen (112). A number of studies from the UK (76% of the patients on a low-FODMAP diet were satisfied with their symptom response compared with 54% receiving the standard dietary advice, P = 0.038) (113) and the United States {a significantly higher proportion of patients in the low-FODMAP diet group had a meaningful clinical response, based on the IBS-QOL score, than in the mNICE (modified National Institute for Health and Care Excellence guidelines) group (52% vs 21%; 95% CI [−0.52 to −0.08])} (114).

Prebiotics are typically high-fiber foods that act as food for human microflora with the intention of maintaining balance of these micro-organisms; probiotics are live micro-organisms that promote health benefits through alterations of or interactions with the intestinal microbiome. The data supporting the use of both prebiotics and probiotics is of low quality given the heterogeneity of studies performed. A meta-analysis of 2 RCTs comparing the use of fructooligoaccharides powder (found in foods such as garlic, onion, and asparagus) vs placebo demonstrated a nonstatistically significant improvement in symptoms for both the treatment and placebo groups (83). RCTs demonstrate that ingestion of Lactobacillus plantarum results in a significant reduction of abdominal pain and flatulence in patients with IBS (84,85). In addition, ingestion of Bifidobacterium animalis showed improvement in abdominal distension and associated symptoms in patients with IBS-C (86). Further studies have demonstrated this same strain of probiotics significantly improved bloating, pain, and the sensation of incomplete evacuation (87).

The use and study of cannabis for the relief of symptoms of functional GI disorders, specifically IBS, is met with some skepticism from gastroenterologists. Although it is well known that the cannabinoid is responsible for psychoactive effects, delta-9-tetrahydrocannabinol (THC) has an analgesic effect, studies of its use in patients with IBS are limited. A small RCT by Klooker et al. (88) reported no difference in threshold for discomfort in a barostat study on rectal sensitivity in patients given dronabinol vs placebo. Currently, IBS is not considered as an accepted indication for the prescription of medicinal marijuana.

Aloe vera, although commonly used to heal sunburn, has also been shown to prevent injury of epithelial tissues and acts as a potent stimulant laxative (89). Furthermore, data suggest an anti-inflammatory and analgesic effect which may be beneficial for patients with IBS (89). There are limited data to suggest efficacy in reducing pain and improving quality of life, but one small RCT did demonstrate improvement in IBS symptoms severity score (SSS, 314 ± 83 [mean ± SD] improved to 257 ± 107 after 4 weeks, P = 0.003) with aloe vera use compared with placebo (276 ± 88 [mean ± SD] to 253 ± 100 after 4 weeks, P > 0.05) (90). Furthermore, a meta-analysis of 3 small RCTs showed a trend toward statistically significant improvement in the IBS symptom score for aloe vera compared with placebo (standardized mean difference of the change in severity score 0.41, 95% CI [0.07–0.75], P = 0.02) (89).

Other supplements reportedly used for the control of symptoms of IBS include peppermint oil, STW-5, and turmeric. The proposed mechanism of action for each of these supplements has been previously discussed (or is referenced in Tables 2 and 3). IBGard, a nonprescription formulation of 90 mg of ultrapurified peppermint oil, is readily available to patients and has been shown to be effective at improving IBS symptoms (at 4 weeks, peppermint oil showed 40% reduction in the total symptom score [−1.16 ± 0.807 (mean ± SD)] compared with 24.3% decrease in placebo [−0.7 ± 0.737 (mean ± SD), P = 0.0246]) (92). This effect was seen as early as 24 hours after initiation of treatment (92). A recent meta-analysis by Alammar et al. (93) showed both global symptom improvement (RR 2.39) and improvement in abdominal pain (RR 1.78) in groups using peppermint oil compared with placebo. STW-5, although typically prescribed in patients with FD, has also been shown to improve symptoms of IBS and to reduce severity of abdominal pain (91). Although there are few studies which support the use of turmeric to ameliorate symptoms of IBS, its use has been associated with improvement in symptoms (abdominal pain and discomfort, constipation) by increasing GI motility and activating hydrogen producing bacteria in the colon (94). A recent study by Alt et al. (95) evaluated the benefit of IQP-CL-101 (Xanthofen), a proprietary mixture of anti-inflammatory curcuminoids; this RCT demonstrated statistically significant improvement compared with placebo in IBS SSS at 4 and 8 weeks (at 8 weeks, IQP-CL-101 led to a 113 ± 64.9 [mean ± SD] point reduction compared with placebo which led to 38.7 ± 64.5 [mean ± SD] point reduction in symptom severity, P < 0.001).

Finally, in a recent study published by Zhou et al. (96), the use of glutamine was found overwhelmingly, although likely erroneously because of small sample size, to be efficacious in decreasing IBS symptom severity (baseline of 301.39 ± 53.61 [mean ± SD] improved to 181.39 ± 47.73, P < 0.0001 in the glutamine group compared with 301.63 ± 57.97 [mean ± SD] improved to 296.06 ± 62.3, P = 0.13 in the placebo group). The proposed mechanism of action of glutamine in postinfection IBS is thought to be related to glutamine's role in restoration of normal intestinal permeability to decrease bacterial and toxin translocation after epithelial cell damage as can occur in infection (96). The only adverse events were abdominal pain and bloating, both of which occurred at similar frequency between treatment and placebo groups.

Mind-body medicine

Centrally acting, nonherbal and nonpharmacologic therapies such as cognitive behavioral therapy (CBT), hypnotherapy, and mindfulness-based stress reduction are evidence-based complementary modalities that have been shown to improve symptom severity in patients with IBS. These therapies aim to reduce overactivity to stressors and improve on maladaptive coping behaviors.

CBT focuses on increasing awareness of the association between stressors, thoughts, and symptoms, and then correcting irrational beliefs or negative emotions to cope with symptoms. There have been over 20 RCTs demonstrating that CBT is effective to improve symptoms of IBS when compared with usual medical care, antidepressants or antispasmodic agents, placebo, or support therapies (100,101). A recent meta-analysis reported that the number needed to treat with CBT was 3 (102). There have been multiple theories hypothesized as to why CBT is more effective in alleviating symptoms than other psychological therapies, but no common conclusion has been drawn; authors typically cite stress surrounding IBS symptoms and the management thereof as the etiology for symptom improvement with use of CBT (99).

Gut-directed hypnotherapy uses metaphorical imagery to allow patients to imagine the normalization of GI function and subsequently improve their symptoms (115). Studies report an overall symptom improvement rate of 50%–80% (103). Clinical remission for up to 10 months has been documented in patients with IBS treated with hypnotherapy. The number needed to treat with hypnotherapy was 4 in a recent meta-analysis (102). Furthermore, there have been data suggesting that gut-directed hypnotherapy is as effective as the low-FODMAP diet for relief of GI symptoms in patient with IBS (116).

Historically, acupuncture for the relief of IBS symptoms has had variable results for symptom severity and improvement in quality of life. In a 2012 meta-analyses published by Manheimer, acupuncture was found to be no more effective for IBS symptom severity or quality of life than sham acupuncture (104). A more recent RCT by Lowe et al. (105) reported that in both acupuncture and sham acupuncture groups, IBS symptom score improvement did not significantly differ. Most of the studies regarding acupuncture in IBS are fraught with challenges to create adequate control groups, so interpretation of these studies is difficult.

A meta-analysis including 273 patients showed a beneficial effect of yoga over conventional treatment in IBS with improvement in bowel symptoms, IBS severity, and anxiety (106). All the yoga programs included postures (asana), 3 included breath control (pranayama), and one included meditation or mindfulness-based stress reduction (106). A more recent RCT by the same group showed that there was no statistically significant difference regarding IBS SSS between a group randomized to yoga or a low-FODMAP diet (107).

CONCLUSION

In conclusion, CAM therapies for the treatment of functional bowel disorders are increasing in popularity. A thorough understanding and knowledge base of these modalities is important for the practicing gastroenterologist to form better therapeutic rapport with patients and expand one's armamentarium of treatment options. Gastroenterologists may wish to consider implementing evidence-based CAM therapies in the treatment regimen for functional bowel disease. These therapies may prevent patients from undergoing unnecessary diagnostic testing and ameliorate patients' symptoms more quickly when these therapies are used in conjunction with standard medical therapies.

CONFLICTS OF INTEREST

Guarantor of the article: David J. Hass, MD, FACG.

Specific author contributions: J.K.D., J.L., D.J.H.: wrote and edited the manuscript.

Financial support: None to report.

Potential competing interests: None to report.

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