Updates to the modern diagnosis of GERD: Lyon consensus 2.0.

The Lyon Consensus provides conclusive criteria for and against the diagnosis of gastro-oesophageal reflux disease (GERD), and adjunctive metrics that consolidate or refute GERD diagnosis when primary criteria are borderline or inconclusive. An international core and working group was assembled to evaluate research since publication of the original Lyon Consensus, and to vote on statements collaboratively developed to update criteria. The Lyon Consensus 2.0 provides a modern definition of actionable GERD, where evidence from oesophageal testing supports revising, escalating or personalising GERD management for the symptomatic patient. Symptoms that have a high versus low likelihood of relationship to reflux episodes are described. Unproven versus proven GERD define diagnostic strategies and testing options. Patients with no prior GERD evidence (unproven GERD) are studied using prolonged wireless pH monitoring or catheter-based pH or pH-monitoring off antisecretory medication, while patients with conclusive GERD evidence (proven GERD) and persisting symptoms are evaluated using pH-impedance monitoring while on optimised antisecretory therapy. The major changes from the original Lyon Consensus criteria include establishment of Los Angeles grade B oesophagitis as conclusive GERD evidence, description of metrics and thresholds to be used with prolonged wireless pH monitoring, and inclusion of parameters useful in diagnosis of refractory GERD when testing is performed on antisecretory therapy in proven GERD. Criteria that have not performed well in the diagnosis of actionable GERD have been retired. Personalisation of investigation and management to each patient's unique presentation will optimise GERD diagnosis and management.

Assessment of Esophageal Motility in Patients With Eosinophilic Esophagitis: A Scoping Review.

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated condition causing esophageal symptoms, particularly dysphagia. Despite the important progress in the treatment of EoE, a significant proportion of patients continue to report symptoms that negatively impact quality of life. Esophageal manometry is used to assess motility and function, but is not routinely used in EoE. We aimed to systematically review and describe current literature evaluating esophageal manometry in EoE. Forty-eight studies meeting the criteria were identified, describing 802 patients. Using standard water swallow protocols, the proportion of abnormalities detected was not dissimilar to other populations, apart from disorders of esophago-gastric outflow, which were found in 5%. Twelve studies described pretreatment and posttreatment manometry, with motility normalization after pharmacological therapy reported in 20%. Early, brief panesophageal pressurization was described in a number of studies and was more prevalent in the few studies utilizing additional provocation testing. Reports in the literature regarding temporal relationships between manometric findings and symptoms are variable. Esophageal manometry may be capable of detecting clinically relevant changes to esophageal function in EoE. Possible mechanisms are altered neuromuscular function because of secretory products of EoE and/or fibroinflammatory processes, manifesting as pressurization because of altered esophageal compliance. Some changes may be reversible with therapy. Drawing strong conclusions from the literature is difficult, with bias toward case reports and retrospective observation. Adaptations to assessment protocols to include provocation testing may provide more robust evaluation and detect clinically relevant, subtle changes in esophageal function, earlier within the patient pathway.

Tuning Emission Lifetimes of Ir(C

Emissive compounds with long emission lifetimes (µs to ms) in the visible region are of interest for a range of applications, from oxygen sensing to cellular imaging. The emission behavior of Ir(ppy)2(acac) complexes (where ppy is the 2-phenylpyridyl chelate and acac is the acetylacetonate chelate) with an oligo(para-phenyleneethynylene) (OPE3) motif containing three para-rings and two ethynyl bridges attached to acac or ppy is examined here due to the accessibility of the long-lived OPE3 triplet states. Nine Ir(ppy)2(acac) complexes with OPE3 units are synthesized where the OPE3 motif is at the acac moiety (aOPE3), incorporated in the ppy chelate (pOPE3) or attached to ppy via a durylene link (dOPE3). The aOPE3 and dOPE3 complexes contain OPE3 units that are decoupled from the Ir(ppy)2(acac) core by adopting perpendicular ring-ring orientations, whereas the pOPE3 complexes have OPE3 integrated into the ppy ligand to maximize electronic coupling with the Ir(ppy)2(acac) core. While the conjugated pOPE3 complexes show emission lifetimes of 0.69-32.8 µs similar to the lifetimes of 1.00-23.1 µs for the non-OPE3 Ir(ppy)2(acac) complexes synthesized here, the decoupled aOPE3 and dOPE3 complexes reveal long emission lifetimes of 50-625 µs. The long lifetimes found in aOPE3 and dOPE3 complexes are due to intramolecular reversible electronic energy transfer (REET) where the long-lived triplet-state metal to ligand charge transfer (3MLCT) states exchange via REET with the even longer-lived triplet-state localized OPE3 states. The proposed REET process is supported by changes observed in excitation wavelength-dependent and time-dependent emission spectra from aOPE3 and dOPE3 complexes, whereas emission spectra from pOPE3 complexes remain independent of the excitation wavelength and time due to the well-established 3MLCT states of many Ir(ppy)2(acac) complexes. The long lifetimes, visible emission maxima (524-526 nm), and photoluminescent quantum yields of 0.44-0.60 for the dOPE3 complexes indicate the possibility of utilizing such compounds in oxygen-sensing and cellular imaging applications.

Opioid-Induced Esophageal Dysmotility (OIED) - A Case Report.

Recent studies have shown that chronic opioid use is associated with an increased risk of symptomatic esophageal motility disorders. Opioid-induced esophageal dysfunction (OIED) is most often identified in patients taking high doses of opioids. This condition is associated with poorer treatment outcomes than primary motility disorders and management of these cases is further complicated by the presence of chronic pain, opioid addiction, and physical and psychological comorbidity.We present the case of a 68-year-old Caucasian woman with OIED, induced by the chronic intake of low-dose Fentanyl and Tramadol prescribed to treat severe back pain. The clinical course highlights the sometimes difficult diagnosis and management of this recently recognized condition.

How provocative tests in addition to wet swallows during high-resolution manometry can direct clinical management.

PURPOSE OF REVIEW: Provocative tests have been advocated to address limitations of high-resolution manometry (HRM) with wet swallows. We describe the commonly used provocative manometric manoeuvres [rapid drink challenge (RDC), multiple rapid swallows (MRS), solid swallows and the solid test meal (STM)], compare their diagnostic yield and accuracy to wet swallows, and outline their role in directing clinical management. RECENT FINDINGS: Provocative testing with RDC and STM identifies a proportion of achalasia cases missed by standard testing, and RDC can play a similar role to radiology in the evaluation of treatment response. In EGJOO, provocative testing with RDC and STM not only increase the diagnostic yield, but can also help differentiate between spurious cases and those representing true outflow obstruction likely to respond to achalasia-type therapies. MRS and STM can help determine the clinical relevance (or otherwise) of ineffective oesophageal motility, and in this setting, MRS may predict the likelihood of postfundoplication dysphagia. RDC and STM can help identify cases of postfundoplication dysphagia more likely to respond to dilatation. SUMMARY: Provocative testing has been shown to increase diagnostic yield of HRM, clarify inconclusive diagnoses, allows corroboration of dysmotility with patient symptoms and helps direct clinical management.

Validation of the Lyon classification for GORD diagnosis: acid exposure time assessed by prolonged wireless pH monitoring in healthy controls and patients with erosive oesophagitis.

OBJECTIVE: Acid exposure time (AET) from ambulatory pH studies and reflux oesophagitis are independent measurements used by the Lyon classification to diagnose GORD. This study aimed to validate AET reference ranges and diagnostic thresholds by analysis of 96-hour wireless pH studies from healthy, asymptomatic controls (HCs) and patients with and without oesophagitis. DESIGN: HC and consecutive patients referred for wireless pH studies (off acid suppressants for >7 days) underwent 96-hour pH studies at two tertiary referral centres. Erosive oesophagitis was categorised by the Los Angeles (LA) classification. Linear regression and receiver operating curve (ROC) analysis were performed to define optimal diagnostic cut-offs. RESULTS: Prolonged, 96-hour pH studies were completed in 39 HCs (age 28 (18-53) years, 72% female) and 944 patients (age 46 (16-85) years, 65% female), of whom 136 (14.5%) had reflux oesophagitis. Median AET in HC was 1.3% (upper 95th percentile 4.6%) for any study day and 2.6% (upper 95th percentile 6.9%) for the worst day (24-hour period) during the study. ROC analysis for average AET differentiated HC from patients with moderate-to-severe oesophagitis (LA BCD; sensitivity 87%, specificity 95%, positive predictive value (PPV) 59%, negative predictive value 99% for a cut-off AET of 4.3%; area under the receiver operating curve 0.95). Specificity was higher, but PPV was substantially lower for severe oesophagitis (LA CD). 'Worst-day' analysis provided similar results; however, day-to-day variability was high. CONCLUSION: Diagnostic thresholds for average AET were identified that accurately discriminate between HCs and patients with erosive oesophagitis. The findings provide conditional support for diagnostic criteria for GORD proposed by the Lyon Consensus.

Results of a Shortened Quarantine Protocol on a Midwestern College Campus.

A shortened quarantine protocol after severe acute respiratory syndrome coronavirus 2 exposure was implemented on a college campus. We assessed data on exposures, symptoms, and tests in 1152 unvaccinated individuals released from quarantine on day 7. A shortened quarantine period for asymptomatic individuals testing negative can be implemented with low risk.

Response to a COVID-19 Outbreak on a University Campus - Indiana, August 2020.

Institutions of higher education adopted different approaches for the fall semester 2020 in response to the coronavirus disease 2019 (COVID-19) pandemic. Approximately 45% of colleges and universities implemented online instruction, more than one fourth (27%) provided in-person instruction, and 21% used a hybrid model (1). Although CDC has published COVID-19 guidance for institutions of higher education (2-4), little has been published regarding the response to COVID-19 outbreaks on college and university campuses (5). In August 2020, an Indiana university with approximately 12,000 students (including 8,000 undergraduate students, 85% of whom lived on campus) implemented various public health measures to reduce transmission of SARS-CoV-2, the virus that causes COVID-19. Despite these measures, the university experienced an outbreak involving 371 cases during the first few weeks of the fall semester. The majority of cases occurred among undergraduate students living off campus, and several large off-campus gatherings were identified as common sources of exposure. Rather than sending students home, the university switched from in-person to online instruction for undergraduate students and instituted a series of campus restrictions for 2 weeks, during which testing, contact tracing, and isolation and quarantine programs were substantially enhanced, along with educational efforts highlighting the need for strict adherence to the mitigation measures. After 2 weeks, the university implemented a phased return to in-person instruction (with 85% of classes offered in person) and resumption of student life activities. This report describes the outbreak and the data-driven, targeted interventions and rapid escalation of testing, tracing, and isolation measures that enabled the medium-sized university to resume in-person instruction and campus activities. These strategies might prove useful to other colleges and universities responding to campus outbreaks.

Cyclophane Molecules Exhibiting Thermally Activated Delayed Fluorescence: Linking Donor Units to Influence Molecular Conformation.

The synthetic methodology to covalently link donors to form cyclophane-based thermally activated delayed fluorescence (TADF) molecules is presented. These are the first reported examples of TADF cyclophanes with "electronically innocent" bridges between the donor units. Using a phenothiazine-dibenzothiophene-S,S-dioxide donor-acceptor-donor (D-A-D) system, the two phenothiazine (PTZ) donor units were linked by three different strategies: (i) ester condensation, (ii) ether synthesis, and (iii) ring closing metathesis. Detailed X-ray crystallographic, photophysical and computational analyses show that the cyclophane molecular architecture alters the conformational distribution of the PTZ units, while retaining a certain degree of rotational freedom of the intersegmental D-A axes that is crucial for efficient TADF. Despite their different structures, the cyclophanes and their nonbridged precursors have similar photophysical properties since they emit through similar excited states resulting from the presence of the equatorial conformation of their PTZ donor segments. In particular, the axial-axial conformations, known to be detrimental to the TADF process, are suppressed by linking the PTZ units to form a cyclophane. The work establishes a versatile linking strategy that could be used in further functionalization while retaining the excellent photophysical properties of the parent D-A-D system.

Development of a Multinational Clinical Practice Guideline: A Practical Structured Procedure.

INTRODUCTION: The development of a clinical guideline is a challenging process. National and international organizations have established a variety of approaches, grading systems, evaluation scales, and voting modes; however, a practical description which illustrates all steps from starting the initiative to publication and dissemination of the guideline is usually not provided. We describe a structured guideline procedure that can be adjusted to the requirements of other multinational guidelines. METHODS: A group of European specialist gastroenterological societies and national societies initiated a guideline for the use of breath tests in gastroenterology. A balance between scientific evidence and clinical experience was achieved by involving European specialist societies and physicians from 18 European countries. For persons contributing to the guideline process, different levels of involvement were defined. The tasks were assigned to different groups of persons, which formed scientific institutions. RESULTS: We describe organizational structures and institutions, the stepwise approach, and illustrate the multistep guideline development procedure in a flowchart diagram that shows workflow and assigned responsibilities and provides details for the execution of each step, including timelines. The process is split into 4 phases: foundation, preparation, voting, and publication. DISCUSSION: This structured procedure of a gastroenterological clinical practice guideline can serve as a blueprint for future multinational guideline initiatives and may aid future attempts to standardize and harmonize guideline development processes in gastroenterology and in other medical fields. Although the described procedure is for a diagnostic guideline, it may also be appropriate for therapeutic guidelines by adjusting the acceptance criteria for recommendations.

[Physiotherapy for anorectal dysfunctions]. / Physiotherapie bei anorektalen Erkrankungen.

Physiotherapy for anorectal dysfunctions Abstract. Anorectal dysfunctions lead to massive limitations in quality of life, depending on their severity. The invasive interventions have clear indications - successes and risks. In the case of functional disorders, the therapeutic options for the physician are limited. Physiotherapy can make a significant contribution to improving the quality of life.

[Investigations of Anorectal Function]. / Anorektale Funktionsdiagnostik.

Investigations of Anorectal Function Abstract. Investigations of anorectal function allows measurement of anal sphincter pressure, evaluation of rectal sensitivity and verification of rectoanal reflexes, which are essential elements in the assessment of bowel emptying. It is combined with a balloon expulsion test to ensure that the manometric findings are consistent with anorectal function. These tests are used in the diagnostic work-up of chronic defecation disorders, constipation and faecal incontinence, but can also provide clarification in the pre- and post-operative setting, for functional anorectal pain and other disorders of pelvic floor function. Most patients referred for investigation of these symptoms require a comprehensive assessment of anorectal structure and function. Because of the high variability of normal values and complexity of anorectal function, no single examination provides all the information needed to make a symptom-explaining, conclusive diagnosis and influence treatment decisions. Anorectal manometry is useful to assess the extent of impairment of anorectal function and to differentiate between organic and functional disorders (including pelvic floor dyssynergia). A preceding detailed anamnesis as well as endoscopic (procto / rectoscopy) and imaging procedures (anorectal endosonography, dynamic MR defecography) complete the diagnostic investigation instead.

A Second Case of Human Conjunctival Infestation With Thelazia gulosa and a Review of T. gulosa in North America.

We describe a second case of human infection caused by Thelazia gulosa (the cattle eye worm), likely acquired in California. For epidemiologic purposes, it is important to identify all Thelazia recovered from humans in North America to the species level.

Prolonged Wireless pH Monitoring in Patients With Persistent Reflux Symptoms Despite Proton Pump Inhibitor Therapy.

BACKGROUND & AIMS: Wireless pH monitoring measures esophageal acid exposure time (AET) for up to 96 hours. We evaluated competing methods of analysis of wireless pH data. METHODS: Adult patients with persisting reflux symptoms despite acid suppression (n = 322, 48.5 ± 0.9 years, 61.7% women) from 2 tertiary centers were evaluated using symptom questionnaires and wireless pH monitoring off therapy, from November 2013 through September 2017; 30 healthy adults (control subjects; 26.9 ± 1.5 years; 60.0% women) were similarly evaluated. Concordance of daily AET (physiologic <4%, borderline 4%-6%, pathologic>6%) for 2 or more days constituted the predominant AET pattern. Each predominant pattern (physiologic, borderline, or pathologic) in relation to data from the first day, and total averaged AET, were compared with other interpretation paradigms (first 2 days, best day, or worst day) and with symptoms. RESULTS: At least 2 days of AET data were available from 96.9% of patients, 3 days from 90.7%, and 4 days from 72.7%. A higher proportion of patients had a predominant pathologic pattern (31.4%) than control subjects (11.1%; P = .03). When 3 or more days of data were available, 90.4% of patients had a predominant AET pattern; when 2 days of data were available, 64.1% had a predominant AET pattern (P < .001). Day 1 AET was discordant with the predominant pattern in 22.4% of patients and was less strongly associated with the predominant pattern compared with 48 hour AET (P = .059) or total averaged AET (P = .02). Baseline symptom burden was higher in patients with a predominant pathologic pattern compared with a predominant physiologic pattern (P = .02). CONCLUSIONS: The predominant AET pattern on prolonged wireless pH monitoring can identify patients at risk for reflux symptoms and provides gains over 24 hours and 48 hours recording, especially when results from the first 2 days are discordant or borderline.

Evaluation of Acute Mountain Sickness by Unsedated Transnasal Esophagogastroduodenoscopy at High Altitude.

BACKGROUND & AIMS: It is not clear how rapid ascent to a high altitude causes the gastrointestinal symptoms of acute mountain sickness (AMS). We assessed the incidence of endoscopic lesions in the upper gastrointestinal tract in healthy mountaineers after a rapid ascent to high altitude, their association with symptoms, and their pathogenic mechanisms. METHODS: In a prospective study, 25 mountaineers (10 women; mean age, 43.8 ± 9.5 y) underwent unsedated, transnasal esophagogastroduodenoscopy in Zurich (490 m) and then on 2 test days (days 2 and 4) at a high altitude laboratory in the Alps (Capanna Regina Margherita, 4559 m). Symptoms were assessed using validated instruments for AMS (the acute mountain sickness score and the Lake Louise scoring system) and visual analogue scales (scale, 0-100). Levels of messenger RNAs (mRNAs) in duodenal biopsy specimens were measured by quantitative polymerase chain rection. RESULTS: The follow-up endoscopy at high altitude was performed in 19 of 25 patients on day 2 and in 23 of 25 patients on day 4. The frequency of endoscopic lesions increased from 12% at baseline to 26.3% on day 2 and to 60.9% on day 4 (P < .001). The incidence of ulcer disease increased from 0 at baseline to 10.5% on day 2 and to 21.7% on day 4 (P = .014). Mucosal lesions were associated with lower hunger scores (37.3 vs 67.4 in patients without lesions; P = .012). Subjects with peptic lesions had higher levels of HIF2A mRNA, which encodes a hypoxia-induced transcription factor, and ICAM1 mRNA, which encodes an adhesion molecule, compared with subjects without lesions (fold changes, 1.38 vs 0.63; P = .001; and 1.37 vs 0.66; P = .011, respectively). CONCLUSIONS: In a prospective study of 25 mountaineers, fast ascent to a high altitude resulted in rapid onset of clinically meaningful mucosal lesions and ulcer disease. Duodenal biopsy specimens from these subjects had increased levels of HIF2A mRNA and ICAM1 mRNA, which might contribute to the formation of hypoxia-induced peptic lesions. Further studies are needed of the mechanisms of this process.

Impaired micronutrients and prealbumin in patients with established and very early systemic sclerosis.

OBJECTIVES: Gastrointestinal involvement and impaired nutritional status are frequent in patients with systemic sclerosis (SSc). Hereby, we hypothesised that micronutrients and/or prealbumin could be deficitary in SSc. METHODS: Patients with SSc and very early SSc (veSSc) were prospectively included. Clinical assessment, data recording and quality controls followed EUSTAR standards. The UCLA SCTCGIT 2.0 questionnaire was applied and the serum levels of zinc, selenium, prealbumin, holotranscobalamin, folic acid were measured. RESULTS: Half (52.4%) of the 176 patients with established SSc showed a deficiency in at least one of the measured nutrients. The most frequent deficit was seen in folic acid (17.9%), followed closely by selenium, prealbumin and zinc (around 15% each). Nearly a fifth (19%) of these patients had multiple deficiencies. Patients with more severe disease, including advanced skin fibrosis, positive ACR 1980 classification criteria, anemia and elevated serum inflammation markers were more likely to be nutrient deficient. Lower BMI<20kg/m2 was associated with several nutrient deficiencies. Prealbumin deficiency was associated with more frequent stomach symptoms and methotrexate therapy. A third of veSSc patients (27%, 44/74) presented a nutrient deficiency, mostly of zinc (10%). Surprisingly, micronutrient deficiencies were not associated with usual parameters of gastrointestinal involvement. CONCLUSIONS: These novel data reveal deficiencies in micronutrients and/or prealbumin are a frequent burden in patients with SSc. Moreover, these correlate with clinical aspects of the disease. Especially patients with advanced disease appear at high risk for an impaired nutrient status, suggesting that screening of micronutrients status should be performed in these patients.

High-Resolution Manometry-Observations After 15 Years of Personal Use-Has Advancement Reached a Plateau?

PURPOSE OF REVIEW: In the absence of mucosal or structural disease, the aim of investigating the oesophagus is to provide clinically relevant measurements of function that can explain the cause of symptoms, identify pathology and guide effective management. One of the most notable recent advances in the field of oesophageal function has been high-resolution manometry (HRM). This review explores how innovation in HRM has progressed and has far from reached a plateau. RECENT FINDINGS: HRM technology, methodology and utility continue to evolve; simple additions to the swallow protocol (e.g. eating and drinking), shifting position, targeting symptoms and adding impedance sensors to the HRM catheter have led to improved diagnoses, therapeutic decision-making and outcomes. Progress in HRM persists and shows little sign of abating. The next iteration of the Chicago Classification of motor disorders will highlight these advances and will also identify opportunities for further research and innovation.

Update on lactose malabsorption and intolerance: pathogenesis, diagnosis and clinical management.

Lactose is the main source of calories in milk, an essential nutriedigestion, patients with visceral hypersensitivity nt in infancy and a key part of the diet in populations that maintain the ability to digest this disaccharide in adulthood. Lactase deficiency (LD) is the failure to express the enzyme that hydrolyses lactose into galactose and glucose in the small intestine. The genetic mechanism of lactase persistence in adult Caucasians is mediated by a single C→T nucleotide polymorphism at the LCTbo -13'910 locus on chromosome-2. Lactose malabsorption (LM) refers to any cause of failure to digest and/or absorb lactose in the small intestine. This includes primary genetic and also secondary LD due to infection or other conditions that affect the mucosal integrity of the small bowel. Lactose intolerance (LI) is defined as the onset of abdominal symptoms such as abdominal pain, bloating and diarrhoea after lactose ingestion by an individual with LM. The likelihood of LI depends on the lactose dose, lactase expression and the intestinal microbiome. Independent of lactose digestion, patients with visceral hypersensitivity associated with anxiety or the Irritable Bowel Syndrome (IBS) are at increased risk of the condition. Diagnostic investigations available to diagnose LM and LI include genetic, endoscopic and physiological tests. The association between self-reported LI, objective findings and clinical outcome of dietary intervention is variable. Treatment of LI can include low-lactose diet, lactase supplementation and, potentially, colonic adaptation by prebiotics. The clinical outcome of these treatments is modest, because lactose is just one of a number of poorly absorbed carbohydrates which can cause symptoms by similar mechanisms.

Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All-Organic Donor-Acceptor Systems.

Thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) are known to occur in organic D-A-D and D-A systems where the donor group contains the phenothiazine unit and the acceptor is dibenzothiophene- S, S-dioxide. This study reports the synthesis and characterization of one new D-A and four new D-A-D systems with methoxy groups on the phenothiazine to examine their effect on emission properties in the zeonex matrix. X-ray analysis and highly specialized NMR techniques were used to characterize asymmetric methoxy-substituted derivative 3b, which is chiral at N because of an extremely high flipping barrier at the phenothiazine N atom. Based on hybrid-density functional theory computations, the methoxy substituents tune the relative stabilities of the axial conformers with respect to equatorial conformers of the phenothiazine units, depending on their substitution position. This conformational effect significantly influences both TADF and RTP contributions compared to the parent D-A-D system. It is also demonstrated that the equatorial forms of D-A-D and D-A systems in zeonex exhibit TADF. Additionally, the methoxy groups promote luminescence in D-A-D systems where only axial conformers exist. This work reveals further design opportunities for more efficient TADF and RTP molecules.

Effect of cocoa on the brain and gut in healthy subjects: a randomised controlled trial.

Dark chocolate is claimed to have effects on gastrointestinal function and to improve well-being. This randomised controlled study tested the hypothesis that cocoa slows gastric emptying and intestinal transit. Functional brain imaging identified central effects of cocoa on cortical activity. Healthy volunteers (HV) ingested 100 g dark (72 % cocoa) or white (0 % cocoa) chocolate for 5 d, in randomised order. Participants recorded abdominal symptoms and stool consistency by the Bristol Stool Score (BSS). Gastric emptying (GE) and intestinal and colonic transit time were assessed by scintigraphy and marker studies, respectively. Combined positron emission tomography-computed tomography (PET-CT) imaging assessed regional brain activity. A total of sixteen HV (seven females and nine males) completed the studies (mean age 34 (21-58) years, BMI 22·8 (18·5-26·0) kg/m2). Dark chocolate had no effect on upper gastrointestinal function (GE half-time 82 (75-120) v. 83 (60-120) min; P=0·937); however, stool consistency was increased (BSS 3 (3-5) v. 4 (4-6); P=0·011) and there was a trend to slower colonic transit (17 (13-26) v. 21 (15-47) h; P=0·075). PET-CT imaging showed increased [18F]fluorodeoxyglucose (FDG) in the visual cortex, with increased FDG uptake also in somatosensory, motor and pre-frontal cortices (P<0·001). In conclusion, dark chocolate with a high cocoa content has effects on colonic and cerebral function in HV. Future research will assess its effects in patients with functional gastrointestinal diseases with disturbed bowel function and psychological complaints.