• Health-related quality of life
• Inflammatory bowel disease
• Interoception
• Irritable bowel syndrome
• Visceral hypersensitivity

• Humans
• Irritable Bowel Syndrome/complications
• Quality of Life
• Inflammatory Bowel Diseases/complications
• Inflammatory Bowel Diseases/diagnosis
• Inflammatory Bowel Diseases/psychology
• Stomach
• Emotions

• bowel dysfunction
• brain injury
• constipation
• fecal incontinence
• rehabilitation

• Crohn’s disease
• IL-6
• IL-6Rα
• Mendelian randomization
• brain cortical structure
• inflammatory bowel disease
• ulcerative colitis

• Abdominal pain
• Bowel inflammation
• Brain neuroplasticity
• Central sensitization
• Intestinal hypersensitivity

• Corticotropin-Releasing Hormone
• Humans
• Hyperalgesia/etiology
• Neuronal Plasticity
• Nociception
• Pain/complications

• 18-015-00055 Russian Foundation for Basic Research

Electroacupuncture (EA) relieves visceral hypersensitivity (VH) with underlying inflammatory bowel diseases. However, the mechanism by which EA treats ileitis-induced VH is not clearly known. To assess the effects of EA on ileitis-induced VH and confirm whether EA attenuates VH through spinal PAR-2 activation and CGRP release, goats received an injection of 2,4,6-trinitro-benzenesulfonic-acid (TNBS) solution into the ileal wall. TNBS-injected goats were allocated into VH, Sham acupuncture (Sham-A) and EA groups, while goats treated with saline instead of TNBS solution were used as the control. Goats in EA group received EA at bilateral Hou-San-Li acupoints for 0.5 h at 7 days and thereafter repeated every 3 days for 6 times. Goats in the Sham-A group were inserted with needles for 0.5 h at the aforementioned acupoints without any hand manipulation and electric stimulation. Visceromotor responses to colorectal distension, an indicator of VH, were recorded by electromyography. The terminal ileum and thoracic spinal cord (T₁₁) were sampled for evaluating ileitis at days 7 and 22, and distribution and expression-levels of PAR-2, CGRP and c-Fos on day 22. TNBS-treated-goats exhibited apparent transmural-ileitis on day 7, microscopically low-grade ileitis on day 22 and VH at days 7–22. Goats of Sham-A, VH or EA group showed higher (P < 0.01) VH at days 7–22 than the Control-goats. EA-treated goats exhibited lower (P < 0.01) VH as compared with Sham-A or VH group. Immunoreactive-cells and expression-levels of spinal PAR-2, CGRP and c-Fos in the EA group were greater (P < 0.01) than those in the Control group, but less (P < 0.01) than those in Sham-A and VH groups on day 22. Downregulation of spinal PAR-2 and CGRP levels by EA attenuates the ileitis and resultant VH.

Inflammatory bowel disease (IBD), mainly comprising Crohn’s disease and ulcerative colitis, is characterized by chronic inflammation in the digestive tract. Approximately 60% of the patients experience abdominal pain during acute IBD episodes, which severely impairs their quality of life. Both peripheral and central mechanisms are thought to be involved in such abdominal pain in IBD. Although much attention has been paid to peripheral mechanisms of abdominal pain in IBD pathophysiology, the involvement of supraspinal mechanisms remains poorly understood. To address this issue, we investigated regional brain activity in response to colorectal distension in normal and IBD model rats using voxel-based statistical analysis of 2-deoxy-2-[18F]fluoro-_D-glucose positron emission tomography imaging. The rat IBD model was generated by colorectal administration of 2,4,6-trinitrobenzene sulfonic acid, a chemical compound widely used to generate colitis. Tissue damage and inflammation were induced and dynamically changed with time after 2,4,6-trinitrobenzene sulfonic acid injection, while colorectal distension-induced visceromotor response showed corresponding temporal changes. We found that characteristic brain activations were observed in response to visceral innocuous and noxious colorectal distension and supraspinal nociception shared some physiological sensory pathway. Moreover, widespread brain regions were activated, and the functional coupling between the central medial thalamic nucleus and anterior cingulate cortex was enhanced after noxious colorectal distension in IBD model of rats. Increased brain activity in the anterior insular cortex and anterior cingulate cortex was positively correlated with noxious colorectal distension-induced pain severity in normal and IBD rats, respectively. These findings suggest that the pain matrix was shifted following persistent colonic inflammation, and thalamocortical sensitization in the pathway from the central medial thalamic nucleus to anterior cingulate cortex might be a central mechanism of the visceral hyperalgesia in IBD pathophysiology.

• Inflammatory bowel disease
• abdominal pain
• functional coupling
• pain matrix shifted
• persistent colonic inflammation

Background: Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, exhibiting complex and controversial pathological features. Both oxidative stress and inflammation-related reactive oxygen species production may be involved in IBS pathological development. Thus, we focused on several aspects regarding the causes of oxidative stress occurrence in IBS. Additionally, in the molecular context of oxidative changes, we tried to discuss these possible neurological implications in IBS. Methods: The literature search included the main available databases (e.g., ScienceDirect, Pubmed/Medline, Embase, and Google Scholar). Articles in the English language were taken into consideration. Our screening was conducted based on several words such as “irritable bowel syndrome”, “gut brain axis”, “oxidative stress”, “neuroendocrine”, and combinations. Results: While no consistent evidence suggests clear pathway mechanisms, it seems that the inflammatory response may also be relevant in IBS. The mild implication of oxidative stress in IBS has been described through clinical studies and some animal models, revealing changes in the main markers such as antioxidant status and peroxidation markers. Moreover, it seems that the neurological structures involved in the brain-gut axis may be affected in IBS rather than the local gut tissue and functionality. Due to a gut-brain axis bidirectional communication error, a correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress can be suggested. Conclusions: Therefore, there is a possible correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress that are not followed by tissue destruction in IBS patients. Moreover, it is not yet clear whether oxidative stress, inflammation, or neurological impairments are key determinants or in which way these three interact in IBS pathology. However, the conditions in which oxidative imbalances occur may be an interesting research lead in order to find possible explanations for IBS development.

• irritable bowel syndrome
• neurological deficiencies
• oxidative stress

• Brain/physiopathology
• Humans
• Irritable Bowel Syndrome/complications
• Irritable Bowel Syndrome/etiology
• Irritable Bowel Syndrome/physiopathology
• Models, Neurological
• Neurodegenerative Diseases/blood
• Neurodegenerative Diseases/etiology
• Neurosecretory Systems
• Oxidative Stress/physiology

• alexithymia
• hypothalamic-pituitary adrenal axis
• inflammatory bowel disease
• interoceptive abilities
• irritable bowel syndrome

Functional brain imaging (positron emission tomography – PET, functional magnetic resonance imaging – fMRI), allowing in vivo analysis of the brain-digestive tract interaction and the neurological mechanisms underlying visceral hypersensitivity, significantly advanced research and helped in the understanding of the interrelations in this field. Differences in this parameter can result from alterations in task-related cognitive states or from resting state processes. Nowadays, advanced imaging techniques such as fMRI are more frequently used and are acknowledged among both clinicians and radiologists in the diagnostic algorithm of digestive tract diseases. Functional dyspepsia is a condition in which neuroimaging allows for analysis of dysfunctions within the brain-gut axis (BGA) engaged in processing of visceral discomfort and pain. The results of studies in patient groups with irritable bowel syndrome prove that psychosocial factors significantly affect the mechanisms regulating visceral sensitivity within the brain. The BGA includes neuronal pathways (autonomic nervous system), neuroendocrine (hypothalamo-pituitary-adrenal axis), and neuroimmunological ones. Psychological processes affect the functioning of the digestive system and can cause dyspeptic symptoms. A patient’s mental condition associated with stress can affect processes taking place in the central nervous system and trigger somatic reactions in the digestive tract through the autonomic visceral system.

• functional dyspepsia
• functional magnetic resonance imaging
• irritable bowel syndrome
• resting state

Crohn's disease (CD) has been known to cause both abdominal pain alongside functional and structural alterations in the central nervous system (CNS) in affected patients. This study seeks to determine the alternations of metabolites in the bilateral anterior cingulate cortex (ACC) of CD patients with abdominal pain by using proton magnetic resonance spectroscopy (¹H-MRS) to further explore the neural mechanism.

Sixteen CD patients with abdominal pain and 13 CD patients without abdominal pain, were recruited alongside 20 healthy controls (HCs) for this study. Clinical evaluations, including the 0–10 Visual Analogue Scale (VAS) of pain, Hospital Anxiety and Depression Scale (HADS) and Crohn's Disease Activity Index (CDAI), were evaluated prior to MR scanning. This study selected the bilateral ACC as the region of interest (ROI). The metabolites of the bilateral ACC were quantitatively analyzed by LCModel and Gannet. A independent sample t-test and one-way analysis of variance (ANOVA) were performed for statistical analysis. Spearman correlation analyses were performed to examine the relationship between the metabolite levels and clinical evaluations.

The results indicated that CD patients with abdominal pain exhibited significantly higher levels of Glutamate (Glu)/(creatine + phosphocreatine, total creatine, tCr) over CD patients without abdominal pain, and HCs (p = 0.003, 0.009, respectively) in the bilateral ACC. The level of (Glutamate + Glutamine, Glx)/tCr of pain CD group was higher than non-pain CD group (p = 0.022). Moreover, within the pain CD group, Glu/tCr and Glx/tCr levels correlated strongly with the VAS scores of pain (ρ = 0.86, 0.59 respectively, p < 0.05). Meanwhile, the results indicates that CD patients with abdominal pain have significantly lower levels of γ-aminobutyric acid plus (GABA+)/tCr (p = 0.002) than HCs. To some extent, CDAI demonstrated a trend of negative correlation with GABA+/tCr levels (p = 0.088, ρ = −0.60).

The neural mechanism of CD patients with abdominal pain in pain processing is tightly associated with neurochemical metabolites. An imbalance in Glu and GABA may play a key role in abdominal pain processing for patients with CD. This mechanism of pain may associate with the intestinal microbiota on the brain-gut axis.

•

The brain metabolite in CD patients with abdominal pain was firstly investigated.

• Brain-gut axis
• Crohn's disease
• Glutamate
• Metabolite
• Pain
• Spectroscopy

• 5-HT3 receptor blockade
• Abdominal pain
• Caudal ventrolateral medulla
• Colitis
• Granisetron
• Nucleus tractus solitarius

• adolescents
• children
• constipation
• fMRI
• fecal incontinence

Irritable bowel syndrome (IBS) is associated with exaggerated cerebral response including emotional processing following visceral stimulation; though data on this issue is available in female IBS patients, it is scanty among males. Hence, we aimed to study brain response of male IBS patients following rectal balloon distension as compared to healthy controls using functional magnetic resonance imaging (fMRI). Data between diarrhea and constipation predominant IBS (IBS-D and IBS-C) were also compared.

Rectal balloon distension threshold was assessed in 20 male IBS patients (10 IBS-C and 10 IBS-D) and 10 age-matched male healthy controls. Subsequently, fMRI on all the participants was performed at their respective rectal pain threshold. The fMRI data were analysed using the Statistical Parametric Mapping software.

IBS patients showed greater cerebral activations in insula, middle temporal gyrus, and cerebellum in the left hemisphere compared to healthy controls. Neural activation was found in bilateral precuneus/superior parietal lobules in controls but not in patients with IBS. The brain activation differed among IBS-C and IBS-D patients; while the right mid-cingulate cortex was activated in IBS-C, the left inferior orbito-frontal cortex, left calcarine, and bilateral fusiform gyri were activated among patients with IBS-D following rectal balloon distension.

Brain response to rectal balloon distension differed among male patients with IBS and controls and among patients with IBS-C and IBS-D. Differential activation among patients with IBS-C and IBS-D was seen in the brain regions controlling affective motivation, homeostatic emotions, and autonomic responses to pain.

• Brain
• Irritable bowel syndrome
• Magnetic resonance imaging
• Pain

• Brain
• Functional magnetic resonance imaging
• Functional neuroimaging
• Gastrointestinal diseases

• functional magnetic resonance imaging
• irritable bowel syndrome
• inflammatory bowel disease
• interoception

• TNBS
• calcitonin gene-related peptide
• crohn’s disease
• cytokines
• ileitis
• rat
• visceral hypersensitivity
• visceromotor response

Provoked vestibulodynia is the most common form of vulvodynia. Despite its high prevalence and deleterious sexual, conjugal, and psychological repercussions, effective evidence-based interventions for provoked vestibulodynia remain limited. For a high proportion of women, significant pain persists despite the currently available treatments. Growing evidence suggests that the central nervous system (CNS) could play a key role in provoked vestibulodynia; thus, treatment targeting the CNS, rather than localized dysfunctions, may be beneficial for women suffering from provoked vestibulodynia. In this study, we aim to build on the promising results of a previous case report and evaluate whether transcranial direct-current stimulation, a non-invasive brain stimulation technique targeting the CNS, could be an effective treatment option for women with provoked vestibulodynia.

This single-center, triple-blind, parallel group, randomized, controlled trial aims to compare the efficacy of transcranial direct-current stimulation with sham transcranial direct-current stimulation in women with provoked vestibulodynia. Forty women diagnosed with provoked vestibulodynia by a gynecologist, following a standardized treatment protocol, are randomized to either active transcranial direct-current stimulation treatment for ten sessions of 20 minutes at an intensity of 2 mA or sham transcranial direct-current stimulation over a 2-week period. Outcome measures are collected at baseline, 2 weeks after treatment and at 3-month follow-up. The primary outcome is pain during intercourse, assessed with a numerical rating scale. Secondary measurements focus on the sexual function, vestibular pain sensitivity, psychological distress, treatment satisfaction, and the patient’s global impression of change.

To our knowledge, this study is the first randomized controlled trial to examine the efficacy of transcranial direct-current stimulation in women with provoked vestibulodynia. Findings from this trial are expected to provide significant information about a promising intervention targeting the centralization of pain in women with provoked vestibulodynia.

Clinicaltrials.gov, NCT02543593. Registered on September 4, 2015.

The online version of this article (doi:10.1186/s13063-016-1366-5) contains supplementary material, which is available to authorized users.

• Chronic pain
• Dyspareunia
• Psychological distress
• Randomized clinical trial
• Sexual dysfunction
• Transcranial direct-current stimulation
• Treatment outcome
• Vestibulodynia

• Adult
• Aged
• Analgesics, Opioid/therapeutic use
• Brain/drug effects
• Brain/physiopathology
• Colonoscopy/methods
• Conscious Sedation/methods
• Female
• Humans
• Hypnotics and Sedatives/therapeutic use
• Male
• Midazolam/therapeutic use
• Middle Aged
• Nociception/physiology
• Pain/drug therapy
• Pain/physiopathology
• Pain Management/methods
• Spectroscopy, Near-Infrared

• R01 GM104986 NIGMS NIH HHS
• R01-GM104986 NIGMS NIH HHS

• Brain-Gut axis
• Gut microbiota
• Stress
• Visceral Pain

• Animals
• Brain/metabolism
• Clinical Trials as Topic/methods
• Gastrointestinal Microbiome/physiology
• Gastrointestinal Tract/metabolism
• Humans
• Irritable Bowel Syndrome/metabolism
• Irritable Bowel Syndrome/psychology
• Stress, Psychological/metabolism
• Stress, Psychological/psychology
• Visceral Pain/metabolism
• Visceral Pain/psychology

• I01 BX002188 BLRD VA
• IK6 BX003610 BLRD VA

Pain in chronic pancreatitis (CP) shows similarities with other visceral pain syndromes (i.e., inflammatory bowel disease and esophagitis), which should thus be managed in a similar fashion. Typical causes of CP pain include increased intrapancreatic pressure, pancreatic inflammation and pancreatic/extrapancreatic complications. Unfortunately, CP pain continues to be a major clinical challenge. It is recognized that ongoing pain may induce altered central pain processing, e.g., central sensitization or pro-nociceptive pain modulation. When this is present conventional pain treatment targeting the nociceptive focus, e.g., opioid analgesia or surgical/endoscopic intervention, often fails even if technically successful. If central nervous system pain processing is altered, specific treatment targeting these changes should be instituted (e.g., gabapentinoids, ketamine or tricyclic antidepressants). Suitable tools are now available to make altered central processing visible, including quantitative sensory testing, electroencephalograpy and (functional) magnetic resonance imaging. These techniques are potentially clinically useful diagnostic tools to analyze central pain processing and thus define optimum management approaches for pain in CP and other visceral pain syndromes. The present review proposes a systematic mechanism-orientated approach to pain management in CP based on a holistic view of the mechanisms involved. Future research should address the circumstances under which central nervous system pain processing changes in CP, and how this is influenced by ongoing nociceptive input and therapies. Thus we hope to predict which patients are at risk for developing chronic pain or not responding to therapy, leading to improved treatment of chronic pain in CP and other visceral pain disorders.

• Chronic pancreatitis
• Pain
• Pain treatment
• Central sensitization
• Quantitative sensory testing
• Electroencephalograpy
• Magnetic resonance imaging

• Analgesics/therapeutic use
• Animals
• Central Nervous System/drug effects
• Central Nervous System/physiopathology
• Chronic Pain/diagnosis
• Chronic Pain/drug therapy
• Chronic Pain/etiology
• Chronic Pain/physiopathology
• Critical Pathways
• Humans
• Pain Management/methods
• Pain Measurement
• Pain Perception/drug effects
• Pain Threshold/drug effects
• Pancreatitis, Chronic/complications
• Pancreatitis, Chronic/diagnosis
• Pancreatitis, Chronic/drug therapy
• Pancreatitis, Chronic/physiopathology
• Predictive Value of Tests
• Treatment Outcome

• central sensitization
• colitis
• inflammatory bowel diseases
• spinal cord
• visceral pain

• Irritable bowel syndrome
• rectal barostat
• rectal sensitivity
• transcranial magnetic stimulation

• Adult
• Cross-Over Studies
• Double-Blind Method
• Female
• Humans
• Irritable Bowel Syndrome/physiopathology
• Irritable Bowel Syndrome/therapy
• Male
• Middle Aged
• Motor Cortex
• Pain Measurement
• Pain Threshold/physiology
• Pilot Projects
• Pressure
• Rectum/physiopathology
• Transcranial Magnetic Stimulation/methods
• Treatment Outcome

• Gray matter volume
• Interindividual differences
• Rectal distension
• Rectal pain threshold
• Rectal sensory threshold
• Visceral sensitivity
• Voxel-based morphometry

Patients with irritable bowel syndrome (IBS) are characterized by abnormal central processing with altered brain activation in response to visceral nociceptive signals. The effect of electroacupuncture (EA) on IBS patients is unclear. The study is set to study the effect of EA on brain activation during noxious rectal distension in IBS patients using a randomized sham-controlled model.

Thirty IBS-diarrhea patients were randomized to true electroacupuncture or sham acupuncture. Functional MRI was performed to evaluate cerebral activation at the following time points: (1) baseline when there was rectal distension only, (2) rectal distension during application of EA, (3) rectal distension after cessation of EA and (4) EA alone with no rectal distension. Group comparison was made under each condition using SPM5 program.

Rectal distension induced significant activation of the anterior cingulated cortex, prefrontal cortex, thalamus, temporal regions and cerebellum at baseline. During and immediately after EA, increased cerebral activation from baseline was observed in the anterior cingulated cortex, bilateral prefrontal cortex, thalamus, temporal regions and right insula in both groups. However, true electroacupuncture led to significantly higher activation at right insula, as well as pulvinar and medial nucleus of the thalamus when compared to sham acupuncture.

We postulate that acupuncture might have the potential effect of pain modulation in IBS by 2 actions: (1) modulation of serotonin pathway at insula and (2) modulation of mood and affection in higher cortical center via ascending pathway at the pulvinar and medial nucleus of the thalamus.

• Acupuncture
• Irritable bowel syndrome
• Magnetic resonance imaging

• Acupuncture
• Irritable bowel syndrome
• Magnetic resonance imaging

• brain imaging
• pooled analysis
• ibs
• colo-rectal stimulation

• Brain/diagnostic imaging
• Brain/pathology
• Brain/physiology
• Catheterization
• Humans
• Irritable Bowel Syndrome/physiopathology
• Magnetic Resonance Imaging
• Positron-Emission Tomography
• Rectum/physiopathology
• Tomography, Emission-Computed, Single-Photon

• K23 DK069614 NIDDK NIH HHS
• M01 RR001066 NCRR NIH HHS
• DK 069614 NIDDK NIH HHS
• UL1 RR025758 NCRR NIH HHS
• M01-RR-01066 NCRR NIH HHS

• neuroscience
• somatoform disorders
• etiology
• brain imaging

• Brain Mapping/methods
• Diagnostic Imaging/methods
• Humans
• International Classification of Diseases
• Magnetic Resonance Imaging
• Positron-Emission Tomography
• Somatoform Disorders/classification
• Somatoform Disorders/diagnosis

• 064351 Wellcome Trust
• 081672 Wellcome Trust
• WT081672MA Wellcome Trust

AIM: To identify the brain loci that process human biliary sensation.

METHODS: In 6 patients (age range: 42-74 years; 4 men), who underwent percutaneous transhepatic biliary drainage (PTBD), the distal biliary tract was stimulated by repeatedly inflating the balloon of the PTBD catheter so that it reached volumes that produced a definite painless sensation. The functional magnetic resonance imaging (fMRI) of the cortical response to biliary sensation was examined.

RESULTS: Biliary balloon stimulation elicited activation of the insular cortex, prefrontal cortex, and somatosensory cortex (P < 0.001).

CONCLUSION: Biliary balloon stimulation evoked a cerebral cortical response detectable by fMRI.

• Biliary
• Sensation
• Functional magnetic resonance imaging
• Stimulation
• Brain-gut axis

• morphine
• visceral pain
• nociception
• central pain
• pancreatitis

• Abdominal Pain/drug therapy
• Abdominal Pain/etiology
• Abdominal Pain/physiopathology
• Afferent Pathways/diagnostic imaging
• Afferent Pathways/drug effects
• Animals
• Brain/diagnostic imaging
• Brain/drug effects
• Brain Mapping
• Image Processing, Computer-Assisted
• Magnetic Resonance Imaging
• Male
• Morphine/pharmacology
• Narcotics/pharmacology
• Pancreatitis/complications
• Pancreatitis/diagnostic imaging
• Radionuclide Imaging
• Rats
• Rats, Inbred Lew

• R01 NS039041 NINDS NIH HHS
• CA73005 NCI NIH HHS
• R01 NS036041-05 NINDS NIH HHS

• Adult
• Attention/physiology
• Brain/physiopathology
• Brain Mapping/methods
• Esophagus/innervation
• Humans
• Magnetic Resonance Imaging/methods
• Male
• Pain/physiopathology
• Pain Measurement
• Physical Stimulation
• Reference Values
• Somatosensory Cortex/physiopathology
• Young Adult

• G0300195 Medical Research Council

• Abdominal Pain/diagnosis
• Abdominal Pain/etiology
• Abdominal Pain/pathology
• Adolescent
• Age Factors
• Case-Control Studies
• Child
• Chronic Disease
• Cohort Studies
• Crohn Disease/complications
• Crohn Disease/diagnosis
• Crohn Disease/pathology
• Female
• Gastrointestinal Diseases/diagnosis
• Gastrointestinal Diseases/etiology
• Gastrointestinal Diseases/pathology
• Humans
• Irritable Bowel Syndrome/diagnosis
• Irritable Bowel Syndrome/etiology
• Irritable Bowel Syndrome/pathology
• Male
• Manometry
• Pain Measurement
• Pain Threshold
• Probability
• Rectum/innervation
• Rectum/pathology
• Reference Values
• Risk Assessment
• Sensitivity and Specificity
• Sensory Thresholds
• Viscera/innervation
• Viscera/pathology

• Animals
• Brain/physiopathology
• Consciousness
• Evoked Potentials, Somatosensory
• Hyperalgesia/etiology
• Hyperalgesia/physiopathology
• Male
• Physical Stimulation/adverse effects
• Physical Stimulation/methods
• Rats
• Rats, Wistar
• Restraint, Physical
• Viscera/physiopathology

• R24 AT002681 NCCIH NIH HHS

• Abdominal Pain/etiology
• Abdominal Pain/psychology
• Abdominal Pain/therapy
• Child
• Gastrointestinal Diseases/etiology
• Gastrointestinal Diseases/psychology
• Gastrointestinal Diseases/therapy
• Humans

Along with the development of nerve imaging, brain function imaging technique is gradually used in the research of functional gastrointestinal disorders (FGID), and it provides a new method for further investigation of the relationship between brain cortex function, gut function and FGID, as well as the relationship between brain and digestive tract. This review focuses on the major progress in the overseas study of irritable bowel syndrome using positron emission tomography and functional magnetic resonance imaging, the problems and application prospect.

• Irritable bowel syndrome
• Brain function imaging
• Functional gastrointestinal disorder