Functional dyspepsia: A critical appraisal of the European consensus from a global perspective
Baha Moshiree
Atrium Health Division of Gastroenterology, Hepatology and Nutrition, Charlotte, North Carolina, USA
Search for more papers by this authorCorresponding Author
Nicholas J. Talley
Faculty of Health and Medicine, University of Newcastle, Newcastle, NSW, Australia
NHMRC Centre of Research Excellence in Digestive Health, Newcastle, NSW, Australia
Australian GI Research Alliance (AGIRA, Newcastle, NSW, Australia
Correspondence
Nicholas J. Talley, Faculty of Health and Medicine, University of Newcastle, Newcastle, NSW, Australia.
Email: [email protected]
Search for more papers by this authorBaha Moshiree
Atrium Health Division of Gastroenterology, Hepatology and Nutrition, Charlotte, North Carolina, USA
Search for more papers by this authorCorresponding Author
Nicholas J. Talley
Faculty of Health and Medicine, University of Newcastle, Newcastle, NSW, Australia
NHMRC Centre of Research Excellence in Digestive Health, Newcastle, NSW, Australia
Australian GI Research Alliance (AGIRA, Newcastle, NSW, Australia
Correspondence
Nicholas J. Talley, Faculty of Health and Medicine, University of Newcastle, Newcastle, NSW, Australia.
Email: [email protected]
Search for more papers by this authorFunding information
No funding declared.
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Abstract
The European Society for Neurogastroenterology and Motility's (ESNM) consensus document on functional dyspepsia (FD) has provided a critical review of the evidence for 36 statements highly relevant to the diagnosis and treatment of FD. We provide here our expert opinion on the North American, Australian and Asian assessments of the same topics discussed, and provide evidence where the ESNM consensus may deviate from those in the other continents. New and exciting data about the pathogenesis of FD are emerging including the possible central role of duodenal micro-inflammation (most notably eosinophilic duodenitis and intestinal mast cell disease), but this is a very dynamic field with several gaps remaining in our understanding that are summarized in this review. Identification of non-invasive biomarkers and testing of targeted therapies, including assessing the benefits of multidisciplinary teams in the management of FD, should be future priorities.
CONFLICT OF INTEREST
Dr. Talley reports, non-financial support from HVN National Science Challenge NZ, personal fees from Aviro Health (Digestive health) (2019), Anatara Life Sciences, Brisbane (2019), Allakos (gastric eosinophilic disease) (2021), Bayer [IBS] (2020), Danone (Probiotic) (2018), Planet Innovation (Gas capsule IBS) (2020), Takeda, Japan (gastroparesis) (2019), Viscera Labs, (USA 2019), twoXAR (2019) (IBS drugs), Viscera Labs, (USA 2021) (IBS-diarrhea), Dr Falk Pharma (2020) (EoE), Censa, Wellesley MA USA (2019) (Diabetic gastroparesis), Cadila Pharmaceuticals (CME) (2019), Progenity Inc. San Diego, (USA 2019) (Intestinal capsule), Sanofi-aventis, Sydney (2019) (Probiotic), Glutagen (2020) (Celiac disease), ARENA Pharmaceuticals (2019) (Abdominal pain), IsoThrive (2021) (oesophageal microbiome), BluMaiden (2021) outside the submitted work; In addition, Dr. Talley has a patent Nepean Dyspepsia Index (NDI) 1998, Biomarkers of IBS licensed, a patent Licensing Questionnaires Talley Bowel Disease Questionnaire licensed to Mayo/Talley, a patent Nestec European Patent licensed, and a patent Singapore Provisional Patent “Microbiota Modulation Of BDNF Tissue Repair Pathway” issued. Committees: Australian Medical Council (AMC) [Council Member]; Australian Telehealth Integration Program; MBS Review Taskforce; NHMRC Principal Committee (Research Committee) Asia Pacific Association of Medical Journal Editors. Boards: GESA Board Member, Sax Institute, Committees of the Presidents of Medical Colleges. Community group: Advisory Board, IFFGD (International Foundation for Functional GI Disorders). Miscellaneous: Avant Foundation (judging of research grants). Editorial: Medical Journal of Australia (Editor in Chief), Up to Date (Section Editor), Precision and Future Medicine, Sungkyunkwan University School of Medicine, South Korea, Med (Journal of Cell Press). Dr. Talley is supported by funding from the National Health and Medical Research Council (NHMRC) to the Centre for Research Excellence in Digestive Health and he holds an NHMRC Investigator grant. No other disclosures.
REFERENCES
- 1 European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia. NGM pending review.
- 2Stanghellini V, Chan FKL, Hasler WL, et al. Gastroduodenal disorders. Gastroenterology. 2016; 150: 1380-1392.
- 3Tack J, Talley NJ, Camilleri M, et al. Functional gastroduodenal disorders. Gastroenterology. 2006; 130: 1466-1479.
- 4Ronkainen J, Aro P, Walker MM, et al. Duodenal eosinophilia is associated with functional dyspepsia and new onset gastro-oesophageal reflux disease. Aliment Pharmacol Ther. 2019; 50(1): 24-32.
- 5Moayyedi PM, Lacy BE, Andrews CN, et al. ACG and CAG clinical guideline: management of dyspepsia. Am J Gastro. 2017; 112: 988-1013.
- 6Oh JH, Kwon JG, Jung HK, et al. Functional Dyspepsia Research Group and Clinical Practice Guidelines Group Under the Korean Society of Neurogastroenterology and Motility. Clinical practice guidelines for functional dyspepsia in Korea. J Neurogastroenterol Motil. 2020; 26(1): 29-50.
- 7Lacy BE, Cangemi D, Vazquez-Roque M. Management of chronic abdominal distension and bloating. Clin Gastroenterol Hepatol. 2021; 19(2): 219-231. PMID: 32246999.
- 8Miwa H, Ghoshal UC, Gonlachanvit S, et al. Asian consensus report on functional dyspepsia. J Neurogastroenterol Motil. 2012; 18: 150-168.
- 9Fujikawa Y, Tominaga K, Tanaka F, et al. Postprandial symptoms felt at the lower part of the epigastrium and a possible association of pancreatic exocrine dysfunction with the pathogenesis of functional dyspepsia. Intern Med. 2017; 56(13): 1629-1635.
- 10Lacy BE, Pimentel M, Brenner DM, et al. ACG clinical guideline: management of irritable bowel syndrome. Am J Gastroenterol. 2021; 116(1): 17-44.
- 11Mahadeva S, Goh KL. Anxiety, depression and quality of life differences between functional and organic dyspepsia. J Gastroenterol Hepatol. 2011; 26(suppl 3): 49-52.
- 12Ronkainen J, Aro P, Jones M, et al. Duodenal eosinophilia and the link to anxiety: A population-based endoscopic study. Neurogastroenterol Motil. 2021:e14109. https://doi.org/10.1111/nmo.14109. Epub ahead of print. PMID: 33687126.
- 13El-Serag HB, Talley NJ. Health-related quality of life in functional dyspepsia. Aliment Pharmacol Ther. 2003; 18(4): 387-393.
- 14Yao X, Yang Y, Zhang S, Shi Y, Zhang Q, Wang Y. The impact of overlapping functional dyspepsia, belching disorders and functional heartburn on anxiety, depression and quality of life of Chinese patients with irritable bowel syndrome. BMC Gastroenterol. 2020; 20(1): 209.
- 15Mani J, Madani S, Thomas R. Economic impact and prognostic factors of functional dyspepsia in children. J Pediatr Gastroenterol Nutr. 2020; 70(4): e65-e70.
- 16Talley NJ. Functional dyspepsia: new insights into pathogenesis and therapy. Korean J Intern Med. 2016; 31: 444-456.
- 17Tack J, Talley NJ. Functional dyspepsia–symptoms, definitions and validity of the Rome III criteria. Nat Rev Gastroenterol Hepatol. 2013; 10: 134-141.
- 18Delgado-Aros S, Camilleri M, Cremonini F, Ferber I, Stephens D, Burton DD. Contributions of gastric volumes and gastric emptying to meal size and postmeal symptoms in functional dyspepsia. Gastroenterology. 2004; 127: 1685-1694.
- 19Bisschops R, Karamanolis G, Arts J, et al. Relationship between symptoms and ingestion of a meal in functional dyspepsia. Gut. 2008; 57: 1495-1503.
- 20Talley NJ, Walker MM, Aro P, et al. Non-ulcer dyspepsia and duodenal eosinophilia: an adult endoscopic population-based case-control study. Clin Gastroenterol Hepatol. 2007; 5: 1175-1183.
- 21Pasricha PJ, Colvin R, Yates K, et al. Characteristics of patients with chronic unexplained nausea and vomiting and normal gastric emptying. Clin Gastroenterol Hepatol. 2011; 9(7): 567-576.e4.
- 22Bredenoord AJ, Chial HJ, Camilleri M, Mullan BP, Murray JA. Gastric accommodation and emptying in evaluation of patients with upper gastrointestinal symptoms. Clin Gastroenterol Hepatol. 2003; 1(4): 264-272. PMID: 15017667.
- 23Vijayvargiya P, Jameie-Oskooei S, Camilleri M, Chedid V, Erwin PJ, Murad MH. Association between delayed gastric emptying and upper gastrointestinal symptoms: a systematic review and meta-analysis. Gut. 2019; 68(5): 804-813.
- 24Tziatzios G, Gkolfakis P, Papanikolaou IS, et al. High prevalence of small intestinal bacterial overgrowth among functional dyspepsia patients. Dig Dis. 2021; 39(4): 382-390. https://doi.org/10.1159/000511944
- 25Gurusamy SR, Shah A, Talley NJ, et al. Small intestinal bacterial overgrowth in functional dyspepsia: a systematic review and meta-analysis. Am J Gastroenterol. 2021; 116(5): 935-942. https://doi.org/10.14309/ajg.0000000000001197
- 26Shanahan ER, Shah A, Koloski N, et al. Influence of cigarette smoking on the human duodenal mucosa-associated microbiota. Microbiome. 2018; 6(1): 150.
- 27Zhong L, Shanahan ER, Raj A, et al. Dyspepsia and the microbiome: time to focus on the small intestine. Gut. 2017; 66(6): 1168-1169.
- 28Fukui A, Takagi T, Naito Y, et al. Higher levels of Streptococcus in upper gastrointestinal mucosa associated with symptoms in patients with functional dyspepsia. Digestion. 2020; 101(1): 38-45.
- 29Su T, Lai S, Lee A, He X, Chen S. Meta-analysis: proton pump inhibitors moderately increase the risk of small intestinal bacterial overgrowth. J Gastroenterol. 2018; 53(1): 27-36. https://doi.org/10.1007/s00535-017-1371-9.
- 30Weitsman S, Celly S, Leite G, et al. Effects of proton pump inhibitors on the small bowel and stool microbiomes. Dig Dis Sci. 2021 Feb 3. https://doi.org/10.1007/s10620-021-06857-y. Epub ahead of print. PMID: 33534012.
- 31Walker MM, Salehian SS, Murray CE, et al. Implications of eosinophilia in the normal duodenal biopsy – an association with allergy and functional dyspepsia. Aliment Pharmacol Ther. 2010; 31: 1229-1236.
- 32Rothenberg ME, Cohen MB. An eosinophil hypothesis for functional dyspepsia. Clin Gastroenterol Hepatol. 2007; 5: 1147-1148.
- 33Walker MM, Aggarwal KR, Shim LSE, et al. Duodenal eosinophilia and early satiety in functional dyspepsia: confirmation of a positive association in an Australian cohort. J Gastroenterol Hepatol. 2014; 29: 474-479.
- 34Wang X, Li X, Ge W, et al. Quantitative evaluation of duodenal eosinophils and mast cells in adult patients with functional dyspepsia. Ann Diagn Pathol. 2015; 19: 50-56.
- 35Talley NJ, Amol PK, Chey WD, et al. Endoscopy and Systematic Biopsy of Patients with Chronic Gastrointestinal Symptoms Leads to High Discovery Rate of Patients Who Meet Histologic Criteria for Eosinophilic Gastritis and/or Eosinophilic Duodenitis. Gastroenterology 2021. Abstract submitted to Digestive Diseases Week.
- 36Kindt S, Tertychnyy A, de Hertogh G, Geboes K, Tack J. Intestinal immune activation in presumed post-infectious functional dyspepsia. Neurogastroenterol Motil. 2009; 21: 832-e56.
- 37Olausson EA, Storsrud S, Grundin H, Isaksson M, Attvall S, Simren M. A small particle size diet reduces upper gastrointestinal symptoms in patients with diabetic gastroparesis: a randomized controlled trial. Am J Gastroenterol. 2014; 109: 375-385.
- 38Farré R, Vanheel H, Vanuytsel T, et al. In functional dyspepsia, hypersensitivity to postprandial distention correlates with meal-related symptom severity. Gastroenterology. 2013; 145: 566-573.
- 39Feinle-Bisset C, Vozzo R, Horowitz M, Talley NJ. Diet, food intake, and disturbed physiology in the pathogenesis of symptoms in functional dyspepsia. Am J Gastroenterol. 2004; 99(1): 170-181.
- 40Duncanson K, Burns G, Pryor J, et al. Mechanisms of food-induced symptom induction and dietary management in functional dyspepsia. Nutrients. 2021; 13(4): 1109.
- 41Tuck CJ, Vanner SJ. Dietary therapies for functional bowel symptoms: recent advances, challenges, and future directions. Neurogastroenterol Motil. 2018; 30(1):e13238.
- 42Shepherd SJ, Lomer MC, Gibson PR. Short-chain carbohydrates and functional gastrointestinal disorders. Am J Gastroenterol. 2013; 108(5): 707-717.
- 43Iacovou M, Tan V, Muir JG, Gibson PR. The low FODMAP diet and its application in East and Southeast Asia. J Neurogastroenterol Motil. 2015; 21(4): 459-470.
- 44Potter MDE, Duncanson K, Jones MP, Walker MM, Keely S, Talley NJ. Wheat sensitivity and functional dyspepsia: a pilot, double-blind, randomized, placebo-controlled dietary crossover trial with novel challenge protocol. Nutrients. 2020; 12(7): 1947.
- 45Fritscher-Ravens A, Pflaum T, Mösinger M, et al. Many patients with irritable bowel syndrome have atypical food allergies not associated with immunoglobulin E. Gastroenterology. 2019; 157(1): 109-118.
- 46Boettcher E, Crowe SE. Dietary proteins and functional gastrointestinal disorders. Am J Gastroenterol. 2013; 108(5): 728-736. https://doi.org/10.1038/ajg.2013.97
- 47Feinle-Bisset C. Upper gastrointestinal sensitivity to meal-related signals in adult humans – relevance to appetite regulation and gut symptoms in health, obesity and functional dyspepsia. Physiol Behav. 2016; 162: 69-82.
- 48Tuck CJ, Reed DE, Muir JG, Vanner SJ. Implementation of the low FODMAP diet in functional gastrointestinal symptoms: a real-world experience. Neurogastroenterol Motil. 2020; 32(1):e13730.
- 49Carvalho RV, Lorena SL, Almeida JR, Mesquita MA. Food intolerance, diet composition, and eating patterns in functional dyspepsia patients. Dig Dis Sci. 2010; 55(1): 60-65.
- 50Gonlachanvit S. Are rice and spicy diet good for functional gastrointestinal disorders? J Neurogastroenterol Motil. 2010; 16(2): 131-138.
- 51 European Food Safety Authority (EFSA), Donohoe T, Garnett K, Lansink AO, Afonso A, Noteborn H. Emerging risks identification on food and feed – EFSA. EFSA J. 2018; 16(7):e05359. https://doi.org/10.2903/j.efsa.2018.5359. PMID: 32625991
- 52Talley NJ, Powell N, Walker MM, et al. Role of smoking in functional dyspepsia and irritable bowel syndrome: three random population-based studies. Aliment Pharmacol Ther. 2021; 54(1): 32-42. https://doi.org/10.1111/apt.16372
- 53Moayyedi P, Talley NJ, Fennerty MB, Vakil N. Can the clinical history distinguish between organic and functional dyspepsia? JAMA. 2006; 295(13): 1566-1576. https://doi.org/10.1001/jama.295.13.1566. PMID: 16595759.
- 54Vakil N, Moayyedi P, Fennerty MB, Talley NJ. Limited value of alarm features in the diagnosis of upper gastrointestinal malignancy: systematic review and meta-analysis. Gastroenterology. 2006; 131(2): 390-401; quiz 659-60.
- 55Mizrahi JD, Surana R, Valle JW, Shroff RT. Pancreatic cancer. Lancet. 2020; 395(10242): 2008-2020. https://doi.org/10.1016/S0140-6736(20)30974-0
- 56Kim GH, Liang PS, Bang SJ, Hwang JH. Screening and surveillance for gastric cancer in the United States: is it needed? Gastrointest Endosc. 2016; 84(1): 18-28.
- 57Liou JM, Lin JT, Wang HP, et al. The optimal age threshold for screening upper endoscopy for uninvestigated dyspepsia in Taiwan, an area with a higher prevalence of gastric cancer in young adults. Gastrointest Endosc. 2005; 61(7): 819-825.
- 58Kumar S, Metz DC, Ellenberg S, Kaplan DE, Goldberg DS. Risk factors and incidence of gastric cancer after detection of Helicobacter pylori infection: a large cohort study. Gastroenterology. 2020; 158(3): 527-536.e7.
- 59Harvey RF, Lane JA, Nair P, et al. Clinical trial: prolonged beneficial effect of Helicobacter pylori eradication on dyspepsia consultations – the Bristol Helicobacter Project. Aliment Pharmacol Ther. 2010; 32(3): 394-400.
- 60Chiang TH, Chang WJ, Chen SL, et al. Mass eradication of Helicobacter pylori to reduce gastric cancer incidence and mortality: a long-term cohort study on Matsu Islands. Gut. 2021; 70(2): 243-250.
- 61Lee AA, Rao K, Parkman HP, et al. Baseline predictors of longitudinal changes in symptom severity and quality of life in patients with suspected gastroparesis. Clin Gastroenterol Hepatol. 2020 Sep 21: S1542-3565(20)31293-3.
10.1016/j.cgh.2020.09.032 Google Scholar
- 62Lee AA, Rao S, Nguyen LA, et al. Validation of diagnostic and performance characteristics of the wireless motility capsule in patients with suspected gastroparesis. Clin Gastroenterol Hepatol. 2019; 17(9): 1770-1779.e2.
- 63Hasler WL, Rao SSC, McCallum RW, et al. Influence of gastric emptying and gut transit testing on clinical management decisions in suspected gastroparesis. Clin Transl Gastroenterol. 2019; 10(10):e00084.
- 64Kaji M, Fujiwara Y, Shiba M, et al. Prevalence of overlaps between GERD, FD and IBS and impact on health-related quality of life. J Gastroenterol Hepatol. 2010; 25(6): 1151-1156.
- 65Parkman HP, Yates KP, Hasler WL, et al. Dietary intake and nutritional deficiencies in patients with diabetic or idiopathic gastroparesis. Gastroenterology. 2011; 141(2): 486-498.e7.
- 66Talley NJ, Meineche-Schmidt V, Pare P, et al. Efficacy of omeprazole in functional dyspepsia: double-blind, randomized, placebo-controlled trials (the Bond and Opera studies). Aliment Pharmacol Ther. 1998; 12: 1055-1065.
- 67Talley NJ, Vakil N, Lauritsen K, et al. Randomized-controlled trial of esomeprazole in functional dyspepsia patients with epigastric pain or burning: does a 1-week trial of acid suppression predict symptom response? Aliment Pharmacol Ther. 2007; 26(5): 673-682.
- 68Suzuki H, Kusunoki H, Kamiya T, et al. Effect of lansoprazole on the epigastric symptoms of functional dyspepsia (ELF study): a multicentre, prospective, randomized, double-blind, placebo-controlled clinical trial. United European Gastroenterol J. 2013; 1(6): 445-452.
- 69Pinto-Sanchez MI, Yuan Y, Hassan A, Bercik P, Moayyedi P. Proton pump inhibitors for functional dyspepsia. Cochrane Database Syst Rev. 2017; 11(11): CD011194.
- 70Sanaka M, Yamamoto T, Kuyama Y. Effects of proton pump inhibitors on gastric emptying: a systematic review. Dig Dis Sci. 2010; 55: 2431-2440.
- 71Wang WH, Huang JQ, Zheng GF, et al. Effects of proton-pump inhibitors on functional dyspepsia: a meta-analysis of randomized placebo-controlled trials. Clin Gastroenterol Hepatol. 2007; 5(2): 178-185.
- 72Gwee KA, Hwang JE, Ho KY, Yeoh KG, Lum CF, Ang PK. In-practice predictors of response to proton pump inhibitor therapy in primary care patients with dyspepsia in an Asian population. J Clin Gastroenterol. 2008; 42(2): 134-138.
- 73Wauters L, Ceulemans M, Frings D, et al. Proton pump inhibitors reduce duodenal eosinophilia, mast cells, and permeability in patients with functional dyspepsia. Gastroenterology. 2021; 160(5): 1521-1531.e9.
- 74Potter MDE, Wood NK, Walker MM, Jones MP, Talley NJ. Proton pump inhibitors and suppression of duodenal eosinophilia in functional dyspepsia. Gut. 2019; 68(7): 1339-1340.
- 75Lombardo L, Foti M, Ruggia O, Chiecchio A. Increased incidence of small intestinal bacterial overgrowth during proton pump inhibitor therapy. Clin Gastroenterol Hepatol. 2010; 8(6): 504-508. https://doi.org/10.1016/j.cgh.2009.12.022.
- 76Almario CV, Chey WD, Speigel MBR. Increased risk of COVID-19 among users of proton pump inhibitors. Am J Gastroenterol. 2020; 65: 1707-1715.
- 77Miner PB Jr, Allgood LD, Grender JM. Comparison of gastric pH with omeprazole magnesium 20.6 mg (Prilosec OTC) o.m. famotidine 10 mg (Pepcid AC) b.d. and famotidine 20 mg b.d. over 14 days of treatment. Aliment Pharmacol Ther. 2007; 25(1): 103-109.
- 78Moayyedi P, Soo S, Deeks J, Delaney B, Innes M, Forman D. Pharmacological interventions for non-ulcer dyspepsia. Cochrane Database Syst Rev. 2006;(4): CD001960.
- 79Ford AC, Moayyedi P, Black CJ, et al. Systematic review and network meta-analysis: efficacy of drugs for functional dyspepsia. Aliment Pharmacol Ther. 2021; 53(1): 8-21.
- 80Braak B, Klooker TK, Wouters MM, Lei A, van den Wijngaard RM, Boeckxstaens GE. Randomised clinical trial: the effects of amitriptyline on drinking capacity and symptoms in patients with functional dyspepsia, a double-blind placebo-controlled study. Aliment Pharmacol Ther. 2011; 34(6): 638-648.
- 81Cheong PK, Ford AC, Cheung CKY, et al. Low-dose imipramine for refractory functional dyspepsia: a randomised, double-blind, placebo-controlled trial. Lancet Gastroenterol Hepatol. 2018; 3(12): 837-844.
- 82Talley NJ, Locke GR, Saito YA, et al. Effect of amitriptyline and escitalopram on functional dyspepsia: a multicenter, randomized controlled study. Gastroenterology. 2015; 149(2): 340-349.e2. https://doi.org/10.1053/j.gastro.2015.04.020
- 83Talley NJ, Tack J, Ptak T, Gupta R, Giguère M. Itopride in functional dyspepsia: results of two phase III multicentre, randomised, double-blind, placebo-controlled trials. Gut. 2008; 57(6): 740-746.
- 84Pittayanon R, Yuan Y, Bollegala NP, et al. Prokinetics for functional dyspepsia: a systematic review and meta-analysis of randomized control trials. Am J Gastroenterol. 2019; 114(2): 233-243.
- 85Tan VP, Liu KS, Lam FY, Hung IF, Yuen MF, Leung WK. Randomised clinical trial: rifaximin versus placebo for the treatment of functional dyspepsia. Aliment Pharmacol Ther. 2017; 45(6): 767-776.
- 86Saneei P, Esmaillzadeh A, Keshteli AH, et al. Combined healthy lifestyle is inversely associated with upper gastrointestinal disorders among Iranian adults. Dig Dis. 2021; 39(1): 77-88.
- 87Basnayake C, Kamm MA, Stanley A, et al. Standard gastroenterologist versus multidisciplinary treatment for functional gastrointestinal disorders (MANTRA): an open-label, single-center, randomized controlled trial. Lancet Gastroenterol Hepatol. 2020; 5(10): 890-899.
- 88Sultan S, Altayar O, Siddique SM, et al. AGA institute rapid review of the gastrointestinal and liver manifestations of COVID-19, meta-analysis of international data, and recommendations for the consultative management of patients with COVID-19. Gastroenterology. 2020; 159(1): 320-334.e27.