--- title: "" url: "https://books.drcassone.com/10/acupuncture-moxibustion-in-the-treatment-of-irritable-bowel-syndrome/190/-" --- # II. Review of Literature ## Western Medicine Viewpoint: **Conventional Diagnosis and Treatment** IBS is broken into subcategories based on the prevailing stool pattern: constipation (IBS-C), diarrhea (IBS-D), mixed constipation and diarrhea (IBS-M), or unsubtyped (IBS-U). Gut dysmotility may also be broken down into four sub-groups: spastic colon syndrome, functional diarrhea, diarrhea-predominant spastic colon syndrome, and midgut dysmotility (Cole, Duncan, & Claydon, 2002). Causative factors for IBS are highly variable and complex and a single pathogenesis has not been identified. Most studies indicate that IBS is associated with visceral hypersensitivity, disruption in gut motility, and abnormal function of the gut-brain axis. Visceral hypersensitivity, and visceral hyperalgesia, are terms used to characterize the internal pain of organs (viscera), in this case specifically describing pain within the gastrointestinal tract. Visceral hypersensitivity, as a benchmark for IBS severity, is used to gauge the progression and remission of IBS (Nozu, Okumura, 2011) as it appears to be the main underlying cause of the abdominal pain symptoms in patients with IBS (Keszthelyi, Troost, & Masclee, 2012). Chronic visceral hypersensitivity involves the brain-gut axis and can manifest in the spinal cord, the periphery, and the central nervous system (Kang, Jia, 2008). The brain-gut axis can affect the outer periphery, the spinal cord, the central nervous system, and various associated neurotransmitters (Weng, 2015). The enteric nervous system is affiliated with the central nervous system, which regulates gastrointestinal function, while  the reciprocal relationships are referred to as brain-gut interactions (Kim and Camilleri, 2000). When attempting to induce bowel sensitivity in patients, through colonic irrigation, the patients suffering IBS show significantly lower pain thresholds compared to healthy patients, which illustrates the visceral hypersensitivity component of IBS (Dong, 2004). Visceral hypersensitivity can be used to differentiate IBS-D from Functional Diarrhea. Although the two ailments present with a similar set of symptoms, only IBS-D presents with abdominal pain that is improved with defecation (Camerilleri, Sellin, and Barrett, 2016).  **Conventional Diagnostics and Differential Diagnoses** Comprehensive stool analysis can identify parasites, fungus, and other infections that need to be ruled out. Helicobactor pylori infections are common and, if discovered, will be treated with a triple antibiotic cocktail; however, this approach causes further damage to the integrity of the gut microbiome, which consequently increases the recurrence rate of infections. Celiac disease must also be excluded when there is severe irritation to the gastrointestinal system. A Positive test will help to eliminate a major dietary cause (gluten containing foods). Endoscopic images are used to rule out pathologies of the upper gastrointestinal tract such as Barrett’s Esophagitis, stomach cancers, gastritis, herniations, ulcers, stenosis, or other visual structure abnormalities. Treatment of upper gastrointestinal tract disorders includes drugs and surgeries. Pancreatic enzymes can be evaluated to rule out pancreatitis, tumors of the pancreas, or diabetic pathologies. Hydrogen breath tests can be used to screen for fruit or lactose malabsorption (in which case, those foods are removed from the diet). Blood tests will show immune system involvement and liver enzyme abnormalities. Colonoscopy images are used to rule out cancers of the colon, diverticulitis, polyps, ulcerations, or structural changes. Biopsies are taken as needed to rule out oncogenesis. Ultrasound equipment is used to check for gallbladder related conditions such as gallstones. If the gallbladder is congested or has stones it will be surgically removed. These differential diagnoses only tell a doctor what the patient does not have. The benefit of exhaustive tests is early detection of time sensitive disease patterns, such as cancer. The downside of these approaches, as they relate to IBS, is that patients end up waiting to get worse before more diagnosable aspects of the disorder manifest. When a diagnosis of IBS has been given, an MD may prescribe psychiatric medications to reduce stress and anxiety. Visceral hypersensitivity correlates to elevations in stress which affect the brain-gut axis (Whitehead, Palsson, 1998). Laxatives are prescribed for IBS-C, while antacids in the form of proton pump inhibitors or H2 antagonists are prescribed generally  for any form of indigestion related to IBS. Anticholinergics, antimotility drugs, and antidiarrheal agents are prescribed for patients with IBS-D (Abdullah and Firmansyah, 2013); however, these drugs also have side effects ranging from drowsiness, abdominal pain, distention, dizziness, nausea, vomiting, constipation, dependency, tolerance, and respiratory depression (Mangel, Bornstein, and Hamm, 2008).  **Additional Western Science Concepts Related to IBS** Purinergic P2X receptors transmit pain signals (Loguercio, 2012). When the intestinal lumen is expanded, adenosine triphosphate (ATP) is released. The P2X receptors open when they bind with extracellular ATP. The stimulus resulting from the stretching triggers the nerve plexus with the P2X receptor located within the mucosal lining, which transmits pain signals to the brain (Burnstock and Kennedy, 2011). When lumenal nociceptors are inflamed they send afferent nerve impulses through dorsal root ganglia (DRG). This triggers a response in the central nervous system (Blackshaw, Brookes, & Grundy, 2007). The P2X receptors generate action potentials (Rong, Spider, & Burnstock, 2002) which means they play a major role in pain signaling for IBS patients. Recurrent hyper-distention of the intestinal lumen results in hyperexcitability of the sensory neurons, and of the central nervous system, which triggers spasms and cramps in the intestines (Shinoda, Feng, & Gebhart, 2009). P2X receptors are crucial in the inflammatory and pain cycles, which is why they are often targets for anti-inflammation and anti-nociception drugs (Kong, Liu, & Xu, 2013).  ATP regulates pain signals by binding to the P2X receptors (Giniatullin and Nistri, 2013), and is also is involved in other IBS related functions such as intestinal motility and gastrointestinal secretions. ATP is held in intestinal secretory cells and transfer signals from peripheral sensory neurons (Tamir, Gershon, 1990). ATP communicates intercellular signals through purinergic receptors (Burnstock, 1997), these signals are introduced to the spinal cord through the dorsal root ganglion, and go to the brainstem via interneurons, which involve the motor neurons of the gastrointestinal tract. Signals are also sent to the pain area of the cerebral cortex to decrease sensation of pain (Zhao, 2008).  The pain relieving mechanism of acupuncture may be due to the binding of adenosine triphosphate (ATP) with purinergic receptors of sensory nerve endings of the skin, which induces a signal conduction pathway for pain modulation in the cerebral cortex. P2X receptors are located throughout the entire body and play a major role in neuropathic, inflammatory, and visceral pain (Xu, Shenoy, and Winston, 2008). Therefore, when reviewing studies involving the treatment of IBS, it is useful to keep in mind the relationship between the P2X receptor and IBS visceral hypersensitivity within the biological feedback loop of the brain-gut axis. In the central nervous system, P2X receptors influence synaptic plasticity and balance neurotransmitters of the dorsal horn in the spinal cord. The P2X receptors of the dorsal root ganglion (DRG) affect sensory neurons and are important in treating ATP-mediated pain in IBS patients (Shinoda, La, & Bielefeldt, 2010).  Brain imaging in patients suffering IBS appears uniquely compared to healthy patients (Elsenbruch, Rosenburg, & Bingel, 2010). IBS patients show distinctly different visceral sensory areas of the brain from healthy populations (Mertz, Morgan, & Tanner, 2000). IBS patients also show changes in blood circulation, carbohydrate metabolism, and processes of the cerebral cortex (Ringel, Drossman, & Turkington, 2003). Rectal irritation through distention has been shown to provoke the anterior cingulate cortex, prefrontal cortex, inferior colliculus, and thalamus (Mertz, Morgan, & Tanner, 2000) illustrating the gut-brain axis. IBS patients display increased dorsolateral prefrontal cortex activity compared to normosensitive patients (Larsson, Tillisch, & Craif, 2012). Brain-gut peptides also modulate gastrointestinal functions and are an important influence on IBS patterns. Excitatory neurotransmitters include histamine, 5-HT, substance P, calcitonin gene-related peptide, and corticotropin-releasing factor-related peptide, while inhibitory neurotransmitters include cholecystokinin, norepinephrine, and vasoactive peptide (Gershon, Tack, 2007).  ## Acupuncture and Oriental Medicine Viewpoint: **Acupuncture and Oriental Medicine Diagnosis and Treatment** Acupuncture and Oriental Medicine (AOM) is a medical model that emphasizes a systems approach to healthcare. Whereas conventional care models view the body as separate parts reductionistically, AOM looks at the big picture holistically. One is not necessarily better than the other in general; however, a systems approach may be more effective, or at least valuable adjunctively, in treating patients with IBS. In China, many doctors consider the AOM approach to be superior to the conventional Western medical approach when treating IBS patients (Tang, 2009). According to AOM, diagnosis is made based on patterns that represent relationships of occurrence within the body which may involve more than one system. For example, IBS is largely considered to be based on one or more of eight core patterns: spleen and stomach qi deficiency, spleen qi deficiency with damp, spleen yang deficiency, kidney yang deficiency, liver qi stagnation, retention of cold damp, retention of damp heat, and retention of food (Anatasi, 2017). Irritable bowel syndrome belongs to the category of disease called diarrhea, constipation, and abdominal pain in Chinese medicine (Zhang, Li, & Wei, 2010); however, treatment will be based on the underlying pattern. The AOM approach also gives a tremendous weight to the emotional state of the patient as possible pathogenesis. Many AOM doctors focus their treatments on the emotional state, with resolution of the emotional state being the primary treatment goal, resulting in improvements in the physical chief complaint. IBS, specifically, is often caused by anxiety or depression (Li, Su, 2011). In IBS patients, the severity of the gastrointestinal symptoms, the level of psychological stress, and abnormal provocation of certain brain regions are related (Drossman, Ringel, & Vogt, 2003). When a patient is no longer stressed, anxious, or depressed then the brain abnormalities connected to visceral hypersensitivity diminish (Chen, Chen, & Yin, 2012). Research supports the evidence that emotional and psychological factors affect IBS which gives reason to emphasize the brain-gut axis. Patients suffering the visceral hypersensitivity of IBS demonstrate increased central reactivity from the outer periphery and also increased visceral sensitivity to central stress events. This further illustrates the brain-gut axis (Fukudo, Nomura, and Muranaka, 1993) and the need for medical models that include emotional and psychological factors in the diagnosis and treatment of IBS. However, most research design leaves no room for individual emotional states to be assessed or considered. This is a core limitation when attempting to justify AOM treatments through Western Science validation. Moxibustion is a form of AOM treatment using the dried leaves of the herb mugwort (Artemisia vulgaris) burned over acupoints. Its therapeutic effect comes from the thermal stimulation combined with the warming and blood moving qualities of the herb. Although the precise mechanisms are unclear, moxibustion benefits come primarily from its  thermal effects (Lee, Kang, 2010). The ability to generate these thermal effects varies based on the quality of the herb used, the size and volume of the moxa cone, and the number of cones applied. There are two primary types of moxa, direct and indirect. Direct moxa is applied directly to the skin whereas indirect moxibustion is applied from a distance to the skin or through an herbal barrier to the skin which can give an additional therapeutic element (e.g. aconite). Moxa also has an important effect on mast cells in the gastrointestinal tract. The number of mast cells, and rate of infiltration and degranulation, are elevated in IBS patients compared to normosensitive patients (Park, Rhee, & Kim, 2006). Moxa stimulates a histamine response that amplifies the effect of mast cells (Pan, Guo, 2009). Moxibustion causes mast cells to degranulate and produce bioactive substances that improve capillary permeability which increases movement of tissue fluid. Moxibustion can increase the number, distribution area, and degranulation of mast cells (Luo, He, & Guo, 2007) which makes it, theoretically, an important treatment for patients suffering IBS. Acupuncture involves the insertion of sterile stainless steel needles into the body for the purpose of stimulating a healing response in the body. The mechanism of action is controversial as it may involve multiple systems. Acupuncture treatments involve the central nervous system, autonomic nervous system, and enteric nervous system (Li, Zhu, and Rong, 2007). Regarding IBS, intestinal motility is at least partially mediated by neural and humoral pathways which acupuncture can influence. Acupuncture also affects serotonergic, cholinergic, and glutaminergic pathways within the brain-gut axis (Schneider, Weiland, & Enck, 2007) which gives us clues to its global or holistic applications. The use of acupuncture targeting serotonergic, cholinergic, and glutamatergic pathways in IBS patients can, theoretically, stimulate endogenous opioids which decrease visceral pain (Ma, Tan, & Yang, 2009). In general, the response acupuncture generates is a subject of much debate; however, it is the aim of this review to capture credibility and efficacy scientifically, regardless of the precise mechanism of function. In China, acupuncture is considered to be effective in the treatment gastrointestinal diseases (Zheng and Zhang, 2016); however, in the United States it is under utilized. Electroacupuncture (EA) is a technique that adds electrical impulse to acupuncture points. It is effective in alleviating both sensory and inflammatory pain (Zhang, Lao, Ren, and Berman, 2014), including the visceral neuropathic pain in IBS patients (Ji, Li, Lin, 2014). QOL scores improve significantly in patients with gastrointestinal diseases when they are treated with acupuncture (Zhang, Yu, and Xu, 2013).