Recommendations for the diagnosis and management of patients with chronic idiopathic diarrhea: Belgian multidisciplinary expert discussion based on a modified Delphi method
Vanuytsel, T; Arts, J; Casneuf, Vet al.
2025 • In Acta Gastro-Enterologica Belgica, 88 (2), p. 217
[en] Background: Chronic diarrhea is one of the more common reasons for referral to a gastro-enterologist. Chronic diarrhea can have a broad range of causes, making it a disease entity with a very extensive differential diagnosis. In a proportion of patients, however, a cause for the chronic diarrhea cannot be found and these patients are said to have chronic idiopathic diarrhea (CID). Methods: A Delphi model was used to establish a diagnostic strategy for patients presenting with chronic diarrhea that maximizes the chance for a positive diagnosis while minimizing the number and invasiveness of the investigations. In addition, the participating experts sought consensus on the different treatment options that can be used in these patients. Results: While a general consensus was reached on the required diagnostic tests for CID, marked differences were observed on the treatment preferences and strategies for these patients among the different experts. The main reason for this is the lack of solid scientific evidence with the different treatment options in this setting (i.e., most data have been generated in patients with IBS-D). Conclusion: the Delphi-like process that was used for this initiative proved to be a useful vehicle to fuel discussions on the management of CID among experts with different backgrounds and to sketch the current clinical practice. (Acta gastroenterol belg., 2025, 88, 179-194).
Disciplines :
Gastroenterology & hepatology
Author, co-author :
Vanuytsel, T; University Hospitals Leuven, Leuven, Belgium, (
Arts, J; AZ Sint-Lucas Brugge, Bruges, Belgium, (
Casneuf, V; OLV Ziekenhuis, Aalst, Belgium, (
De Clerck, F; AZ Sint-Lucas, Ghent, Belgium, (
De Looze, D; ) University Hospital Ghent, Ghent, Belgium, (
Recommendations for the diagnosis and management of patients with chronic idiopathic diarrhea: Belgian multidisciplinary expert discussion based on a modified Delphi method
TALLEY NJ, WEAVER AL, ZINSMEISTER AR, MELTON LJ, 3RD. Onset and disappearance of gastrointestinal symptoms and functional gastrointestinal disorders. Am J Epidemiol 1992,136:165-77.
DESCOTEAUX-FRIDAY GJ, SHRIMANKER I. Chronic Diarrhea. StatPearls 2024.
DIAMOND IR, GRANT RC, FELDMAN BM, PENCHARZ PB, LING SC, MOORE AM, et al. Defining consensus: a systematic review recommends methodologic criteria for reporting of Delphi studies. J Clin Epidemiol 2014,67:401-9.
ARASARADNAM RP, BROWN S, FORBES A, FOX MR, HUNGIN P, KELMAN L, et al. Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition. Gut 2018,67:1380-1399.
SCHILLER LR, PARDI DS, SPILLER R, SEMRAD CE, SURAWICZ CM, GIANNELLA RA, et al. Gastro 2013 APDW/WCOG Shanghai working party report: chronic diarrhea: definition, classification, diagnosis. J Gastroenterol Hepatol 2014,29:6-25.
FOUNDATION R. Rome IV criteria for disorders of gut-brain interaction, 2016.
SINGH P, LEE HN, RANGAN V, BALLOU S, LEMBO J, KATON J, et al. Similarities in Clinical and Psychosocial Characteristics of Functional Diarrhea and Irritable Bowel Syndrome With Diarrhea. Clin Gastroenterol Hepatol 2020,18:399-405.e1.
BHARUCHA AE, ZINSMEISTER AR, SCHLECK CD, MELTON LJ, 3RD. Bowel disturbances are the most important risk factors for late onset fecal incontinence: a population-based case-control study in women. Gastroenterology 2010,139:1559-66.
MACK I, HAHN H, GÖDEL C, ENCK P, BHARUCHA AE. Global Prevalence of Fecal Incontinence in Community-Dwelling Adults: A Systematic Review and Meta-analysis. Clin Gastroenterol Hepatol 2024,22:712-731.e8.
MUSA MK, SAGA S, BLEKKEN LE, HARRIS R, GOODMAN C, NORTON C. The Prevalence, Incidence, and Correlates of Fecal Incontinence Among Older People Residing in Care Homes: A Systematic Review. J Am Med Dir Assoc 2019,20:956-962.e8.
LOUWAGIE V, STEINMAN MD, WANG MH. Fecal impaction in adults. Jaapa 2023,36:19-22.
CHASSANY O, MICHAUX A, BERGMANN JF. Drug-induced diarrhoea. Drug Saf 2000,22:53-72.
MENEES SB, POWELL C, KURLANDER J, GOEL A, CHEY WD. A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS. Am J Gastroenterol 2015,110:444-54.
DAHER R, YAZBECK T, JAOUDE JB, ABBOUD B. Consequences of dysthyroidism on the digestive tract and viscera. World J Gastroenterol 2009,15:2834-8.
DHALIWAL A, ZEINO Z, TOMKINS C, CHEUNG M, NWOKOLO C, SMITH S, et al. Utility of faecal calprotectin in inflammatory bowel disease (IBD): what cut-offs should we apply? Frontline Gastroenterol 2015,6:14-19.
REENAERS C, BOSSUYT P, HINDRYCKX P, VANPOUCKE H, CREMER A, BAERT F. Expert opinion for use of faecal calprotectin in diagnosis and monitoring of inflammatory bowel disease in daily clinical practice. United European Gastroenterol J 2018,6:1117-1125.
QUYN AJ, STEELE RJ, DIGBY J, STRACHAN JA, MOWAT C, MCDONALD PJ, et al. Application of NICE guideline NG12 to the initial assessment of patients with lower gastrointestinal symptoms: not FIT for purpose? Ann Clin Biochem 2018,55:69-76.
WIDLAK MM, THOMAS CL, THOMAS MG, TOMKINS C, SMITH S, O’CONNELL N, et al. Diagnostic accuracy of faecal biomarkers in detecting colorectal cancer and adenoma in symptomatic patients. Aliment Pharmacol Ther 2017,45:354-363.
CARRASCO-LABRA A, LYTVYN L, FALCK-YTTER Y, SURAWICZ CM, CHEY WD. AGA Technical Review on the Evaluation of Functional Diarrhea and Diarrhea-Predominant Irritable Bowel Syndrome in Adults (IBS-D). Gastroenterology 2019,157:859-880.
FERNÁNDEZ-BAÑARES F, ESTEVE M, SALAS A, ALSINA M, FARRÉ C, GONZÁLEZ C, et al. Systematic evaluation of the causes of chronic watery diarrhea with functional characteristics. Am J Gastroenterol 2007,102:2520-8.
ZINGONE F, BAI JC, CELLIER C, LUDVIGSSON JF. Celiac Disease-Related Conditions: Who to Test? Gastroenterology 2024,167:64-78.
ASGHAR Z, THOUFEEQ M, KURIEN M, BALL AJ, REJ A, DAVID TAI FW, et al. Diagnostic Yield of Colonoscopy in Patients With Symptoms Compatible With Rome IV Functional Bowel Disorders. Clin Gastroenterol Hepatol 2022,20:334-341.e3.
CHEY WD, NOJKOV B, RUBENSTEIN JH, DOBHAN RR, GREENSON JK, CASH BD. The yield of colonoscopy in patients with non-constipated irritable bowel syndrome: results from a prospective, controlled US trial. Am J Gastroenterol 2010,105:859-65.
ASGHAR Z, THOUFEEQ M, KURIEN M, BALL AJ, REJ A, DAVID TAI FW, et al. Diagnostic Yield of Colonoscopy in Patients With Symptoms Compatible With Rome IV Functional Bowel Disorders. Clin Gastroenterol Hepatol 2022,20:334-341 e3.
MIEHLKE S, GUAGNOZZI D, ZABANA Y, TONTINI GE, KANSTRUP FIEHN AM, WILDT S, et al. European guidelines on microscopic colitis: United European Gastroenterology and European Microscopic Colitis Group statements and recommendations. United European Gastroenterol J 2021,9:13-37.
TONG J, ZHENG Q, ZHANG C, LO R, SHEN J, RAN Z. Incidence, prevalence, and temporal trends of microscopic colitis: a systematic review and meta-analysis. Am J Gastroenterol 2015,110:265-76; quiz 277.
GENTA RM, SONNENBERG A. The yield of colonic biopsy in the evaluation of chronic unexplained diarrhea. Eur J Gastroenterol Hepatol 2015,27:963-7.
DE VOOGD FAE, VERSTOCKT B, MAASER C, GECSE KB. Point-of-care intestinal ultrasonography in inflammatory bowel disease. Nat Rev Gastroenterol Hepatol 2021,18:209-210.
DUBIAN S, YZET C, BRAZIER F, YZET T, HAUTEFEUILLE V, DECROMBECQUE C, et al. Fecal calprotectin, intestinal ultrasound, and their combination for the diagnosis of inflammatory bowel disease. Clin Res Hepatol Gastroenterol 2025,49:102549.
GIBSON PR, SHEPHERD SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J Gastroenterol Hepatol 2010,25:252-8.
REZAIE A, BURESI M, LEMBO A, LIN H, MCCALLUM R, RAO S, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol 2017,112:775-784.
HAMMER HF, FOX MR, KELLER J, SALVATORE S, BASILISCO G, HAMMER J, et al. European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus. United European Gastroenterol J 2022,10:15-40.
PARKER TJ, WOOLNER JT, PREVOST AT, TUFFNELL Q, SHORTHOUSE M, HUNTER JO. Irritable bowel syndrome: is the search for lactose intolerance justified? Eur J Gastroenterol Hepatol 2001,13:219-25.
CORLEW-ROATH M, DI PALMA JA. Clinical impact of identifying lactose maldigestion or fructose malabsorption in irritable bowel syndrome or other conditions. South Med J 2009,102:1010-2.
HELWIG U, KOCH AK, KOPPKA N, HOLTMANN S, LANGHORST J. The Predictive Value of the Hydrogen Breath Test in the Diagnosis of Fructose Malabsorption. Digestion 2019,99:140-147.
BIESIEKIERSKI JR. Fructose-induced symptoms beyond malabsorption in FGID. United European Gastroenterol J 2014,2:10-3.
GHOSHAL UC, SHUKLA R, GHOSHAL U. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy. Gut Liver 2017,11:196-208.
KASHYAP P, MOAYYEDI P, QUIGLEY EMM, SIMREN M, VANNER S. Critical appraisal of the SIBO hypothesis and breath testing: A clinical practice update endorsed by the European society of neurogastroenterology and motility (ESNM) and the American neurogastroenterology and motility society (ANMS). Neurogastroenterol Motil 2024,36:e14817.
QUIGLEY EMM, MURRAY JA, PIMENTEL M. AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review. Gastroenterology 2020,159:1526-1532.
YU D, CHEESEMAN F, VANNER S. Combined oro-caecal scintigraphy and lactulose hydrogen breath testing demonstrate that breath testing detects oro-caecal transit, not small intestinal bacterial overgrowth in patients with IBS. Gut 2011,60:334-40.
SHAH A, TALLEY NJ, JONES M, KENDALL BJ, KOLOSKI N, WALKER MM, et al. Small Intestinal Bacterial Overgrowth in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies. Am J Gastroenterol 2020,115:190-201.
SAFFOURI GB, SHIELDS-CUTLER RR, CHEN J, YANG Y, LEKATZ HR, HALE VL, et al. Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders. Nat Commun 2019,10:2012.
MULLIN GE. Patient Education. Nutrition in Clinical Practice 2010,25:555-557.
HGR. Aanbevelingen rond diagnostisch onderzoek bij voedselovergevoeligheden. Volume 9509: Hoge gezondheidsraad, 2022.
ATKINSON W, SHELDON TA, SHAATH N, WHORWELL PJ. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 2004,53:1459-64.
WEEKS I, ABBER SR, THOMAS JJ, CALABRESE S, KUO B, STALLER K, et al. The Intersection of Disorders of Gut-Brain Interaction With Avoidant/Restrictive Food Intake Disorder. J Clin Gastroenterol 2023,57:651-662.
SUGAI E, SRUR G, VAZQUEZ H, BENITO F, MAURIFIO E, BOERR LA, et al. Steatocrit: A Reliable Semiquantitative Method for Detection of Steatorrhea. Journal of Clinical Gastroenterology 1994,19.
VOLTA U, ROSTAMI K, AURICCHIO R, LUNDIN KEA. Diagnosis of Seronegative and Ultrashort Celiac Disease. Gastroenterology 2024,167:104-115.
BAKER DE. Loperamide: a pharmacological review. Rev Gastroenterol Disord 2007,7 Suppl 3:S11-8.
MCRORIE JW, JR., MCKEOWN NM. Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber. J Acad Nutr Diet 2017,117:251-264.
DALILE B, VAN OUDENHOVE L, VERVLIET B, VERBEKE K. The role of short-chain fatty acids in microbiota-gut-brain communication. Nat Rev Gastroenterol Hepatol 2019,16:461-478.
WEERTS Z, MASCLEE AAM, WITTEMAN BJM, CLEMENS CHM, WINKENS B, BROUWERS J, et al. Efficacy and Safety of Peppermint Oil in a Randomized, Double-Blind Trial of Patients With Irritable Bowel Syndrome. Gastroenterology 2020,158:123-136.
CLAVÉ P, ACALOVSCHI M, TRIANTAFILLIDIS JK, USPENSKY YP, KALAYCI C, SHEE V, et al. Randomised clinical trial: otilonium bromide improves frequency of abdominal pain, severity of distention and time to relapse in patients with irritable bowel syndrome. Aliment Pharmacol Ther 2011,34:432-42.
BELLINI M, TONARELLI S, NAGY AG, PANCETTI A, COSTA F, RICCHIUTI A, et al. Low FODMAP Diet: Evidence, Doubts, and Hopes. Nutrients 2020,12.
SCHUMANN D, KLOSE P, LAUCHE R, DOBOS G, LANGHORST J, CRAMER H. Low fermentable, oligo-, di-, mono-saccharides and polyol diet in the treatment of irritable bowel syndrome: A systematic review and meta-analysis. Nutrition 2018,45:24-31.
DIONNE J, FORD AC, YUAN Y, CHEY WD, LACY BE, SAITO YA, et al. A Systematic Review and Meta-Analysis Evaluating the Efficacy of a Gluten-Free Diet and a Low FODMAPs Diet in Treating Symptoms of Irritable Bowel Syndrome. Am J Gastroenterol 2018,113:1290-1300.
VAN LANEN AS, DE BREE A, GREYLING A. Efficacy of a low-FODMAP diet in adult irritable bowel syndrome: a systematic review and meta-analysis. Eur J Nutr 2021,60:3505-3522.
ZAHEDI MJ, BEHROUZ V, AZIMI M. Low fermentable oligo-di-mono-saccharides and polyols diet versus general dietary advice in patients with diarrhea-predominant irritable bowel syndrome: A randomized controlled trial. J Gastroenterol Hepatol 2018,33:1192-1199.
PADUANO D, CINGOLANI A, TANDA E, USAI P. Effect of Three Diets (Low-FODMAP, Gluten-free and Balanced) on Irritable Bowel Syndrome Symptoms and Health-Related Quality of Life. Nutrients 2019,11.
GOYAL O, BATTA S, NOHRIA S, KISHORE H, GOYAL P, SEHGAL R, et al. Low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol diet in patients with diarrhea-predominant irritable bowel syndrome: A prospective, randomized trial. J Gastroenterol Hepatol 2021,36:2107-2115.
AZIZ I, TROTT N, BRIGGS R, NORTH JR, HADJIVASSILIOU M, SANDERS DS. Efficacy of a Gluten-Free Diet in Subjects With Irritable Bowel Syndrome-Diarrhea Unaware of Their HLA-DQ2/8 Genotype. Clin Gastroenterol Hepatol 2016,14:696-703.e1.
VAZQUEZ-ROQUE MI, CAMILLERI M, SMYRK T, MURRAY JA, MARIETTA E, O’NEILL J, et al. A controlled trial of gluten-free diet in patients with irritable bowel syndrome-diarrhea: effects on bowel frequency and intestinal function. Gastroenterology 2013,144:903-911.e3.
BIESIEKIERSKI JR, PETERS SL, NEWNHAM ED, ROSELLA O, MUIR JG, GIBSON PR. No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology 2013,145:320-8.e1-3.
SKODJE GI, SARNA VK, MINELLE IH, ROLFSEN KL, MUIR JG, GIBSON PR, et al. Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-Reported Non-Celiac Gluten Sensitivity. Gastroenterology 2018,154:529-539.e2.
WILCOX C, TURNER J, GREEN J. Systematic review: the management of chronic diarrhoea due to bile acid malabsorption. Aliment Pharmacol Ther 2014,39:923-39.
RUIZ-CAMPOS L, GISBERT JP, YSAMAT M, ARAU B, LORAS C, ESTEVE M, et al. Systematic review with meta-analysis: the prevalence of bile acid malabsorption and response to colestyramine in patients with chronic watery diarrhoea and previous cholecystectomy. Aliment Pharmacol Ther 2019,49:242-250.
FERNÁNDEZ-BAÑARES F, ROSINACH M, PIQUERAS M, RUIZ-CERULLA A, MODOLELL I, ZABANA Y, et al. Randomised clinical trial: colestyramine vs. hydroxypropyl cellulose in patients with functional chronic watery diarrhoea. Aliment Pharmacol Ther 2015,41:1132-40.
SCHILLER LR. Good News about BAD. Clin Gastroenterol Hepatol 2020,18:45-47.
GOMES-PORRAS M, CÁRDENAS-SALAS J, ÁLVAREZ-ESCOLÁ C. Somatostatin Analogs in Clinical Practice: a Review. Int J Mol Sci 2020,21.
BISSCHOPS R, DE RUYTER V, DEMOLIN G, BAERT D, MOREELS T, PATTYN P, et al. Lanreotide Autogel in the Treatment of Idiopathic Refractory Diarrhea: Results of an Exploratory, Controlled, Before and After, Open-label, Multicenter, Prospective Clinical Trial. Clin Ther 2016,38:1902-1911.e2.
PLASSE TF, BARTON G, DAVIDSON E, ABRAMSON D, KALFUS I, FATHI R, et al. Bimodal Release Ondansetron Improves Stool Consistency and Symptomatology in Diarrhea-Predominant Irritable Bowel Syndrome: A Randomized, Double-Blind, Trial. Am J Gastroenterol 2020,115:1466-1473.
GARSED K, CHERNOVA J, HASTINGS M, LAM C, MARCIANI L, SINGH G, et al. A randomised trial of ondansetron for the treatment of irritable bowel syndrome with diarrhoea. Gut 2014,63:1617-25.
GUNN D, FORD A, FARRIN A, SPILLER R. Editorial: ondansetron for patients with IBS-D and bowel-predominant symptoms—authors’ reply. Alimentary Pharmacology & Therapeutics 2023,57:1337-1338.
MIN YW, RHEE PL. The clinical potential of ramosetron in the treatment of irritable bowel syndrome with diarrhea (IBS-D). Therap Adv Gastroenterol 2015,8:136-42.
IANIRO G, EUSEBI LH, BLACK CJ, GASBARRINI A, CAMMAROTA G, FORD AC. Systematic review with meta-analysis: efficacy of faecal microbiota transplantation for the treatment of irritable bowel syndrome. Aliment Pharmacol Ther 2019,50:240-248.
MYNEEDU K, DEOKER A, SCHMULSON MJ, BASHASHATI M. Fecal microbiota transplantation in irritable bowel syndrome: A systematic review and meta-analysis. United European Gastroenterol J 2019,7:1033-1041.
HOLVOET T, JOOSSENS M, VÁZQUEZ-CASTELLANOS JF, CHRISTIAENS E, HEYERICK L, BOELENS J, et al. Fecal Microbiota Transplantation Reduces Symptoms in Some Patients With Irritable Bowel Syndrome With Predominant Abdominal Bloating: Short-and Long-term Results From a Placebo-Controlled Randomized Trial. Gastroenterology 2021,160:145-157.e8.