Mechanisms and management of functional abdominal pain

Gut Microbiota and Aging: Traditional Chinese Medicine and Modern Medicine

The changing composition of gut microbiota, much like aging, accompanies people throughout their lives, and the inextricable relationship between both has recently attracted extensive attention as well. Modern medical research has revealed that a series of changes in gut microbiota are involved in the aging process of organisms, which may be because gut microbiota modulates aging-related changes related to innate immunity and cognitive function. At present, there is no definite and effective method to delay aging. However, Nobel laureate Tu Youyou's research on artemisinin has inspired researchers to study the importance of Traditional Chinese Medicine (TCM). TCM, as an ancient alternative medicine, has unique advantages in preventive health care and in treating diseases as it already has formed an independent understanding of the aging system. TCM practitioners believe that the mechanism of aging is mainly deficiency, and pathological states such as blood stasis, qi stagnation and phlegm coagulation can exacerbate the process of aging, which involves a series of organs, including the brain, kidney, heart, liver and spleen. Our current understanding of aging has led us to realise that TCM can indeed make some beneficial changes, such as the improvement of cognitive impairment. However, due to the multi-component and multi-target nature of TCM, the exploration of its mechanism of action has become extremely complex. While analysing the relationship between gut microbiota and aging, this review explores the similarities and differences in treatment methods and mechanisms between TCM and Modern Medicine, in order to explore a new approach that combines TCM and Modern Medicine to regulate gut microbiota, improve immunity and delay aging.

Randomized clinical trial: the effects of pregabalin for centrally mediated abdominal pain syndrome

Background

Pregabalin is worldwidely licensed for the treatment of a variety of pain syndromes and supposed to be a potential candidate for the centrally mediated abdominal pain syndrome (CAPS).

Objectives

To investigate the efficacy of pregabalin on nociceptive and emotional symptoms in CAPS patients.

Design

This is an open-label randomized controlled trial.

Methods

CAPS patients were randomized to receive pregabalin 75 mg (P group), pinaverium bromide 50 mg (PB group), or pregabalin combined pinaverium bromide regimen (P + PB group) three times daily for 4 weeks. Questionnaires were completed biweekly. The primary outcomes were defined as the average abdominal pain scores of severity and frequency at weeks 2 and 4. Secondary outcomes included the reduction in abdominal pain scores, Somatic Self-rating Scale (SSS), Patient Health Questionnaire-15 (PHQ-15), and Generalized Anxiety Disorder Scale 7 (GAD-7) scales obtained at the end of trial to the baseline.

Results

Totally, 102 eligible patients were recruited and randomized. The mean severity scores of abdominal pain were 1.39 ± 1.28, 0.97 ± 1.43 versus 2.91 ± 1.44 (p < 0.0001) in P or PB + P group versus PB group at week 2 and were 0.90 ± 1.21, 1.28 ± 1.87 versus 2.74 ± 1.75 (p < 0.0001) at week 4. The mean frequency scores were 2.55 ± 2.55, 2.03 ± 2.80 versus 5.12 ± 2.09(p < 0.0001) in P or PB + P group versus PB group at week 2 and were 1.72 ± 2.46, 2.00 ± 2.90 versus 4.55 ± 2.55 (p < 0.0001) at week 4. When comparing the changes in SSS, PHQ-15, and GAD-7 scores, patients accepting pregabalin or pregabalin combination regimen reported a more decrease than pinaverium bromide recipients (p = 0.0002, p = 0.0002, and p = 0.0033).

Conclusion

This trial suggests that pregabalin may be beneficial for CAPS abdominal pain and concomitant somatic or anxiety symptoms.

Registration

www.chictr.org.cn (ChiCTR1900028026).

Acupuncture as Part of Multimodal Analgesia for Chronic Pain

Background

Chronic pain is a multifactorial condition that is afflicting populations worldwide causing an increasing economic, physical, mental, and emotional burden. Treatments range from medications to interventional procedures to complementary and alternative medicine (CAM), such as acupuncture. This review aims to discuss the use of acupuncture in the treatment of chronic pain, proposed mechanisms, indications, and efficacy for various chronic pain conditions.

Results

Evidence is varied on the efficacy and quality of data on the use of acupuncture in the treatment of chronic pain. Recent studies have demonstrated promising results in the support of acupuncture for the use in the treatment of cancer, neck, and back pain, functional dyspepsia, and various chronic abdominal pain syndromes.

Conclusion

Acupuncture, deemed well-tolerated and safe to use, has been increasingly studied and is regarded as effective in clinical practice, but its efficacy is limited by the lack of well-conducted, high-quality clinical trials, lower quality evidence, and conflicting study results. Additionally, the exact analgesic mechanism of acupuncture remains to be fully elucidated. Increasing evidence supports the role of acupuncture as therapy in the treatment of cancer, neck, and back pain and functional dyspepsia. Further rigorous studies are needed to fully assess the use of acupuncture in various chronic pain conditions, determine its indications, and optimal treatment schedule. Overall, future studies could benefit from better designed experimental studies, larger groups, and more objectives ways to measure pain reduction and symptom improvement.

Quantitative Assessment of Secondary Healthcare Utilisation by Patients With Functional Abdominal Pain

There is increasing awareness of the impact functional conditions have on the National Health Service (NHS). Less is known about the resources used to manage these conditions. This retrospective quantitative audit aims to determine the demographic and healthcare utilisation of functional abdominal pain patients presenting to the hospital. The most frequent hospital attenders with non-specific abdominal pain in NHS Grampian, 2018-2019, were assessed (n=144). Adult patients meeting the ROME II diagnostic criteria for functional abdominal pain diagnosis were included (n=33). Data were retrospectively collected manually from electronic medical records. Of 33 patients, 93.9% were female, with a mean age of 31.2 years. Each had accessed a mean of 11.5 specialist services, with 69.7% being referred to mental health services; 9.1% had completed treatment. Each patient had a median 4 (range 1-26) emergency/unscheduled presentations to hospital and median 2 (range 0-13) admissions for functional abdominal pain during the study period, with a total of 247 nights spent in hospital by this patient cohort for functional abdominal pain alone. The estimated total cost for these hospital admissions was £593,786.00. Extensive secondary-care input is currently required for patients with functional abdominal pain at a significant cost. Patients are re-presenting to the hospital frequently, which suggests that current management is not effective.

A Comprehensive study of the Abdominal Ganglia Part 1: Celiac, phrenic and superior mesenteric ganglia

INTRODUCTION

Patients with pancreatic cancer, chronic pancreatitis and other abdominal pain syndromes may develop debilitating pain throughout the course of their illness with little to no relief by most conventional methods. While some form of relief is experienced by patients, not all benefit from these procedures and side effects, while transitory in most cases are severe and often not expected. Our aim was therefore to investigate the anatomy surrounding the abdominal sympathetic ganglia, the target for the invasive procedures in an attempt to understand the variations in results.

MATERIALS AND METHODS

The abdominal cavities of nine individuals were dissected and the ganglia investigated, harvested and histologically and immunochemical stained.

RESULTS

The phrenic ganglion was found inconsistently and more often in the left than the right. If present it was located in association with the inferior phrenic artery and often connected to the celiac ganglion. The celiac ganglion was located anterior to the diaphragmatic crus on both sides and specifically posteromedial to the suprarenal gland and superior to the renal artery on the left. On the right it was located posterior to the suprarenal gland and inferior vena cava also superior to the renal vessels. The superior mesenteric ganglion was only positively identified in one individual and was located on the left lateral aspect of the superior mesenteric artery.

CONCLUSION

The blockade procedures for treatment of pain are developed to target the area around the celiac artery where the ganglion is commonly described to be located. However, based on our results of its location and interconnections the ganglion is not located in the targeted area.

Microbiota in health and diseases

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

Chronic Abdominal Pain in General Practice

Background and Summary: Chronic abdominal pain is a challenging complaint for both primary care providers and gastroenterologists alike, due to a broad differential diagnosis and sometimes extensive and negative workup. In the absence of red flag features that herald more acute conditions, the majority of patients with chronic abdominal pain have a benign cause or a functional disorder (e.g., irritable bowel syndrome). The costs associated with a diagnostic workup are an expensive burden to health care. A systematic approach for evaluating patients and initiating a management plan are recommended in the primary care setting. Undiagnosed abdominal pain should be investigated starting with a detailed history and physical examination. Diagnostic investigations should be limited and adapted according to the clinical features, the alarm symptoms, and the symptom severity. This review will focus on the diagnostic tools which general practitioners utilize in the evaluation of chronic abdominal pain. Key Messages: The primary role of the general practitioner is to differentiate an organic disease from a functional one, to refer to a specialist, or to provide treatment for the underlying cause of pain. The functional disorders should be considered after the organic pathology has been confidently excluded. Once a diagnosis of functional pain is established, repetitive testing is not recommended and the patient should be referred to receive psychological support (e.g., cognitive therapy) associated with available pharmacological therapeutic options.

Chronic constipation and abdominal pain: Independent or closely interrelated symptoms?

Constipation is both a symptom and a disorder, seen in both functional constipation and irritable bowel syndrome with constipation predominance (IBS-C). Despite the Rome IV criteria distinguishing between these conditions, they share many therapeutic approaches. This review aims to explore the relationship between constipation and abdominal pain and assess the evidence surrounding whether laxation improves abdominal pain and whether such a response to laxation differs between IBS-C and functional constipation. In patients with functional constipation, increasing frequency of bowel motions by laxatives regardless of mechanism of action is associated with reductions in the severity of abdominal pain, supporting the role of constipation as a contributor to abdominal discomfort. In patients with IBS-C, evidence from systematic reviews indicates that abdominal pain is driven by factors additional to constipation alone and that visceral analgesic modulation is also needed to optimize pain. Changing definitions of IBS-C and heterogeneity in clinical trial design including endpoints have raised uncertainty about the comparative ability of older laxatives without known neuromodulatory effects to improve chronic abdominal pain compared with new secretagogues and prokinetics for the management of IBS-C. While it is known that abdominal pain is associated with constipation and laxation contributes to relief of that pain, it remains unproven whether proposed visceral analgesic properties of new laxatives provide greater pain relief than laxation alone. However, it is likely that the response to laxation in IBS-C is only part of the puzzle.

Comparison of child abuse history in patients with and without functional abdominal pain: a case-control study

BACKGROUND

Gastrointestinal (GI) disorders are ranked first amongst medical diseases as a trigger of requests for mental health counselling. Child abuse has been regarded as one of the main causes of the development of functional abdominal pain (FAP) in children. This study aimed, therefore, to compare the prevalence of child abuse experience among two groups of patients with and without FAP.

METHODS

A case-control study of children in Arak, Iran, in which experience of child abuse was compared in children with (n = 100) and without functional abdominal pain (n = 100). Three categories of child abuse - emotional abuse, physical abuse, and neglect - were assessed using the Child Abuse Questionnaire. The data were analyzed using Stata software.

RESULTS

After adjusting for potential confounders, there were group differences in emotional abuse (96% vs. 81%, aOR = 5.13, 95% CI: 1.3-20.3, p = 0.017), neglect (28% vs. 8%, aOR = 4.27, 95% CI: 1.8-11.8, p = 0.001) and total child abuse score (98% vs. 84%, aOR = 8.2, 95% CI: 1.5-43.8, p = 0.014) but not in physical abuse (57% vs. 46%, aOR = 1.47, 95% CI: 0.81-2.60, p = 0.728).

CONCLUSIONS

As the prevalence of child abuse is higher in patients with FAP, child abuse appears to be related to the occurrence of FAP in children. However, the results of this study cannot be generalized to Iranian society generally and further longitudinal studies are recommended.

Critical evaluation of animal models of visceral pain for therapeutics development: A focus on irritable bowel syndrome

The classification of chronic visceral pain is complex, resulting from persistent inflammation, vascular (ischemic) mechanisms, cancer, obstruction or distension, traction or compression, and combined mechanisms, as well as unexplained functional mechanisms. Despite the prevalence, treatment options for chronic visceral pain are limited. Given this unmet clinical need, the development of novel analgesic agents, with defined targets derived from preclinical studies, is urgently needed. While various animal models have played an important role in our understanding of visceral pain, our knowledge is far from complete. Due to the complexity of visceral pain, this document will focus on chronic abdominal pain, which is the major complaint in patients with disorders of the gut-brain interaction, also referred to as functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Models for IBS are faced with challenges including a complex clinical phenotype, which is comorbid with other conditions including anxiety, depression, painful bladder syndrome, and chronic pelvic pain. Based upon the multifactorial nature of IBS with complicated interactions between biological, psychological, and sociological variables, no single experimental model recapitulates all the symptoms of IBS. This position paper will contextualize chronic visceral pain using the example of IBS and focus on its pathophysiology while providing a critical review of current animal models that are most relevant, robust, and reliable in which to screen promising therapeutics to alleviate visceral pain and delineate the gaps and challenges with these models. We will also highlight, prioritize, and come to a consensus on the models with the highest face/construct validity.

Irritable Bowel Syndrome between Molecular Approach and Clinical Expertise-Searching for Gap Fillers in the Oxidative Stress Way of Thinking

Irritable bowel syndrome (IBS) remains to date an intriguing functional gastrointestinal disorder. Recent studies described a multitude of exogenous factors that work together in IBS, gradually impairing intestinal lining cellular metabolism, including oxidative status balance, with or without a genetic background. Although the current biomarkers support the differentiation between IBS subtypes and other functional gastrointestinal disorder, they are mostly non-specific, referring to clinical, biochemical, and inflammatory imbalances. Since IBS could be also the result of deficient signaling pathways involving both gastrointestinal secretion and neuro-vegetative stimulation, IBS makes no exception from the oxidative hypothesis in the pathological mechanisms. Regarding the oxidative stress implication in IBS, the previous research efforts showed controversial results, with some animal models and patient studies reporting clear oxidative imbalance both on systemic and local levels, but still with no concrete evidence to point to a direct correlation between oxidative stress and IBS. Additionally, it seems that a major role could be also attributed to gut microbiota and their ability to shape our bodies and behaviors. Moreover, the genetic features study in IBS patients showed that several genetic similarities point to a possible correlation of IBS with affective spectrum disorders. Thus, we focus here the discussion on the assumption that IBS could in fact be more likely a stress-related disorder rather than a gastrointestinal one.

The Microbiota-Gut-Brain Axis

The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.

Defining Optimal Care for Functional Gut Disorders - Multi-Disciplinary Versus Standard Care: A Randomized Controlled Trial Protocol

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are the commonest reason for gastroenterological consultation, with patients usually seen by a specialist working in isolation. There is a wealth of evidence testifying to the benefit provided by dieticians, behavioral therapists, hypnotherapists and psychotherapists in treating these conditions, yet they rarely form a part of the therapeutic team, and these treatment modalities are rarely offered as part of the therapeutic management. There has been little examination of different models of care for FGIDs. We hypothesize that multi-disciplinary integrated care is superior to standard specialist-based care in the treatment of functional gut disorders.

METHODS

The "MANTRA" (Multidisciplinary Treatment for Functional Gut Disorders) study compares comprehensive multi-disciplinary outpatient care with standard hospital outpatient care. Consecutive new referrals to the gastroenterology and colorectal outpatient clinics of a single secondary and tertiary care hospital of patients with an FGID, defined by the Rome IV criteria, will be included. Patients will be prospectively randomized 2:1 to multi-disciplinary (gastroenterologist, gut-hypnotherapist, psychiatrist, behavioral therapist ('biofeedback') and dietician) or standard care (gastroenterologist or colorectal surgeon). Patients are assessed up to 12 months after completing treatment. The primary outcome is an improvement on a global assessment scale at the end of treatment. Symptoms, quality of life, psychological well-being, and healthcare costs are secondary outcome measures.

DISCUSSION

There have been few studies examining how best to deliver care for functional gut disorders. The MANTRA study will define the clinical and cost benefits of two different models of care for these highly prevalent disorders.

TRIAL REGISTRATION NUMBER

Clinicaltrials.govNCT03078634 Registered on Clinicaltrials.gov, completed recruitment, registered on March 13th 2017. Ethics and Dissemination: Ethical approval has been received by the St Vincent's Hospital Melbourne human research ethics committee (HREC-A 138/16). The results will be disseminated in peer-reviewed journals and presented at international conferences. Protocol version 1.2.

An Approach to the Patient With Chronic Undiagnosed Abdominal Pain

Abdominal pain is a common reason for referral to a gastroenterologist. The workup of patients with chronic abdominal pain can be extremely challenging as clinicians are responsible for determining whether the patient can be observed or treated symptomatically or this abdominal pain heralds a more systemic disease. The differential is typically wide and given the innervation of the abdomen, localization of abdominal pain does not always provide clear insight into the etiology. This review attempts to help the gastroenterologist narrow down that broad differential and focus on key elements of the patient visit. We emphasize the importance of a detailed history from the patient, along with review-specific details of their history and physical examination that can clue one in about the etiology of the abdominal pain. We review the causes of diffuse abdominal pain that may not first be considered along with uncommon causes of localized abdominal pain. We also review the functional causes of abdominal pain and the importance of identifying these disorders, to avoid unnecessary testing that commonly occurs with these patients.

An acute care approach to functional abdominal pain

Functional abdominal pain disorders are commonly seen in the acute care setting and can be a source of frustration for patients and providers given their inherent chronic nature. However, an understanding of both the general approach to these disorders and the approach to specific common subtypes can help alleviate this frustration and lead to both short-term and long-term therapeutic success. This article describes the pathophysiology of these disorders and outlines a diagnostic and therapeutic approach to commonly seen functional abdominal pain disorders in adults.

Conceptualizing a subtype of patients with chronic pain: The necessity of obtaining a history of sexual abuse

Lifetime history of sexual abuse is estimated to range between 15% and 25% in the general female population. Cross-sectional studies have shown that sexual assault survivors frequently report chronic musculoskeletal pain and functional somatic syndromes. Treating chronic pain with opioids went from being largely discouraged to being included in standards of care and titrating doses until patients self-report adequate control has become common practice, with 8% to 30% of patients with chronic noncancer pain receiving opioids. In this clinical review, we will discuss the association between survivors of sexual assault and chronic pain/functional somatic syndromes. We will further review evidence-based treatment strategies for this "pain-prone phenotype."

Underlying molecular and cellular mechanisms in childhood irritable bowel syndrome

Irritable bowel syndrome (IBS) affects a large number of children throughout the world. The symptom expression of IBS is heterogeneous, and several factors which may be interrelated within the IBS biopsychosocial model play a role. These factors include visceral hyperalgesia, intestinal permeability, gut microbiota, psychosocial distress, gut inflammation, bile acids, food intolerance, colonic bacterial fermentation, and genetics. The molecular and cellular mechanisms of these factors are being actively investigated. In this mini-review, we present updates of these mechanisms and, where possible, relate the findings to childhood IBS. Mechanistic elucidation may lead to the identification of biomarkers as well as personalized childhood IBS therapies.

Common Functional Gastroenterological Disorders Associated With Abdominal Pain

Although abdominal pain is a symptom of several structural gastrointestinal disorders (eg, peptic ulcer disease), this comprehensive review will focus on the 4 most common nonstructural, or functional, disorders associated with abdominal pain: functional dyspepsia, constipation-predominant and diarrhea-predominant irritable bowel syndrome, and functional abdominal pain syndrome. Together, these conditions affect approximately 1 in 4 people in the United States. They are associated with comorbid conditions (eg, fibromyalgia and depression), impaired quality of life, and increased health care utilization. Symptoms are explained by disordered gastrointestinal motility and sensation, which are implicated in various peripheral (eg, postinfectious inflammation and luminal irritants) and/or central (eg, stress and anxiety) factors. These disorders are defined and can generally be diagnosed by symptoms alone. Often prompted by alarm features, selected testing is useful to exclude structural disease. Identifying the specific diagnosis (eg, differentiating between functional abdominal pain and irritable bowel syndrome) and establishing an effective patient-physician relationship are the cornerstones of therapy. Many patients with mild symptoms can be effectively managed with limited tests, sensible dietary modifications, and over-the-counter medications tailored to symptoms. If these measures are not sufficient, pharmacotherapy should be considered for bowel symptoms (constipation or diarrhea) and/or abdominal pain; opioids should not be used. Behavioral and psychological approaches (eg, cognitive behavioral therapy) can be helpful, particularly in patients with chronic abdominal pain who require a multidisciplinary pain management program without opioids.

Gastrointestinal and nutritional issues in joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type

Gastrointestinal involvement is a well known complication of Ehlers-Danlos syndromes (EDSs), mainly in form of abdominal emergencies due to intestinal/abdominal vessels rupture in vascular EDS. In the last decade, a growing number of works investigated the relationship between a wide spectrum of chronic gastrointestinal complaints and various EDS forms, among which the hypermobility type (a.k.a. joint hypermobility syndrome; JHS/EDS-HT) was the most studied. The emerging findings depict a major role for gastrointestinal involvement in the health status and, consequently, management of JHS/EDS-HT patients. Nevertheless, fragmentation of knowledge limits its impact on practice within the boundaries of highly specialized clinics. In this paper, literature review on gastrointestinal manifestations in JHS/EDS-HT was carried out and identified papers categorized as (i) case-control/cohort studies associating (apparently non-syndromic) joint hypermobility and gastrointestinal involvement, (ii) case-control/cohort studies associating JHS/EDS-HT and gastrointestinal involvement, (iii) case reports/series on various gastrointestinal complications in (presumed) JHS/EDS-HT, and (iv) studies reporting gastrointestinal features in heterogeneous EDS patients' cohorts. Gastrointestinal manifestations of JHS/EDS-HT were organized and discussed in two categories, including structural anomalies (i.e., abdominal/diaphragmatic hernias, internal organ/pelvic prolapses, intestinal intussusceptions) and functional features (i.e., dysphagia, gastro-esophageal reflux, dyspepsia, recurrent abdominal pain, constipation/diarrhea), with emphasis on practice and future implications. In the second part of this paper, a summary of possible nutritional interventions in JHS/EDS-HT was presented. Supplementation strategies were borrowed from data available for general population with minor modifications in the light of recent discoveries in the pathogenesis of selected JHS/EDS-HT features.

A Review of Select Centralized Pain Syndromes: Relationship With Childhood Sexual Abuse, Opiate Prescribing, and Treatment Implications for the Primary Care Physician

Pain can be broadly divided into 3 classes, including nociceptive or inflammatory pain (protective), neuropathic (pathological, occurring after damage to the nervous system), or centralized (pathological, due to abnormal function but with no damage or inflammation to the nervous system). The latter has been posited to occur when descending analgesic pathways are attenuated and/or glutamatergic transmission is facilitated. Additionally, this "pain prone phenotype" can be associated with early life trauma and a suboptimal response to opiates. This article will review the relationships between centralized pain syndromes (ie, fibromyalgia, chronic low back pain), childhood sexual abuse, and opiate misuse. Finally, treatment implications, potentially effecting primary care physicians, will be discussed.