Chronic diarrhoea
BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.
Chronic diarrhoea
Laboratory tests
- FBC
- CRP
- Serum electrolytes
- Serum creatinine with eGFR
- TSH
- IgA anti-transglutaminase (after a gluten-rich diet)
- Total IgA
- Stool parasitology on 3 days (if stay in an endemic area, immunosuppression or acute onset)if needednon-French guidelineStay or life in a developing country: UEG/ESNM proposes looking for these pathogens in such patients [2]. Immunosuppression: the BSG recommends examining three fresh stools for eggs, cysts and parasites [1]. Acute onset raising the suspicion of giardiasis [2]. For functional-type diarrhoea, routine testing for stool pathogens is not recommended [2]. Blood hypereosinophilia (> 500/mm³) in a patient back from a tropical stay: stool parasitology, with the Baermann technique to be specified on the request; a single stool examination misses about 9 in 10 cases of strongyloidiasis [3].
- Faecal calprotectin (suspected intestinal inflammation, especially before age 40)if neededLooking for intestinal inflammation (IBD); useful mainly before 40 years when irritable bowel syndrome is suspected. Not reimbursed in France if prescribed by a GP.
- stool culture (with Clostridium difficile testing if after antibiotics)if neededDiarrhoea that started during or after antibiotic treatment: test for Clostridioides difficile.
- fasting plasma glucoseif needednon-French guidelineSecond line: the BSG initial tests do not include plasma glucose (FBC, ferritin, anti-tissue transglutaminase or anti-endomysial antibodies, thyroid tests) and cite diabetes among the possible systemic causes, through dysautonomia [1]; diarrhoea from diabetic neuropathy is not a classic way for diabetes to present (authors' opinion).
- Serum calciumif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- Serum albuminif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- ASTif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- ALTif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- GGTif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- ALPif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- PTif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- Serum ferritinif neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- Vitamin B9 (folate)if neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- Vitamin B12if neededSuspected malabsorption in a young patient; from 50 years, prefer referral for endoscopy.
- HIV serologyif neededImmunocompromised patient, or risk factor or high HIV prevalence in his or her population: chronic diarrhoea is common when HIV infection is discovered.
Child: chronic diarrhoea affecting growth
Laboratory tests
- FBC
- CRP
- Serum albumin
- IgA anti-transglutaminase
- Total IgA
- Serum ferritin (if pallor or anaemia)if neededPallor or anaemia: iron deficiency can reveal coeliac disease, and anaemia points to IBD [17].
- Faecal elastase (if fatty stools or hyperphagia)if neededFatty stools or compensatory hyperphagia: exclude exocrine pancreatic insufficiency [17].
Do not order
Sources (23)
- 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(8):1380-1399.
- Savarino E, Zingone F, Barberio B, Marasco G, Akyuz F, Akpinar H, et al. Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility. United European Gastroenterol J 2022;10(6):556-584.
- Magnaval J-F. Conduite à tenir devant la découverte d'une hyperéosinophilie chez un voyageur. Med Trop (Mars) 2003;63:131-133.
- Agence nationale de sécurité du médicament, base de données publique des médicaments. Glucophage 500 mg, comprimé pelliculé (metformine) : résumé des caractéristiques du produit, rubriques 4.4 et 4.8.
- 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(1):13-37.
- Agence nationale de sécurité du médicament, base de données publique des médicaments. Augmentin 500 mg/62,5 mg, comprimé pelliculé (amoxicilline/acide clavulanique) : résumé des caractéristiques du produit, rubriques 4.4 et 4.8.
- National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE guideline NG12, 23 juin 2015, mise à jour du 15 avril 2026 : section 1.3 (cancers colorectaux).
- Remboursement de la calprotectine fécale
- Assurance maladie. Nomenclature des actes de biologie médicale (NABM), version 105 : examens des selles.
- Schiller LR, Pardi DS, Sellin JH. Chronic Diarrhea: Diagnosis and Management. Clin Gastroenterol Hepatol 2017;15(2):182-193.e3.
- National Institute for Health and Care Excellence. Irritable bowel syndrome in adults: diagnosis and management. Clinical guideline CG61, 23 février 2008, mise à jour du 4 avril 2017.
- National Institute for Health and Care Excellence. Coeliac disease: recognition, assessment and management. NICE guideline NG20, 2 septembre 2015.
- Al-Toma A, Zingone F, Branchi F, Schiepatti A, Malamut G, Canova C, et al. European Society for the Study of Coeliac Disease 2025 Updated Guidelines on the Diagnosis and Management of Coeliac Disease in Adults. United European Gastroenterol J 2025;13(10):1855-1886.
- Haute Autorité de santé. Maladie cœliaque : diagnostic chez l'enfant et l'adulte. Recommandation de bonne pratique, validée par le Collège le 16 juillet 2026.
- Institut national d'excellence en santé et en services sociaux (INESSS). Analyses microbiologiques des selles en cas de diarrhée chez l'adulte et l'enfant : pertinence et pistes d'action pour une utilisation judicieuse. Avis, décembre 2021.
- Burgers K, Lindberg B, Bevis ZJ. Chronic Diarrhea in Adults: Evaluation and Differential Diagnosis. Am Fam Physician. 2020;101(8):472-480.
- Collège national des pédiatres universitaires (CNPU). Référentiel de pédiatrie, chapitre 20 : Diarrhée chronique.
- Husby S, Koletzko S, Korponay-Szabó I, Kurppa K, Mearin ML, Ribes-Koninckx C, et al. European Society Paediatric Gastroenterology, Hepatology and Nutrition guidelines for diagnosing coeliac disease 2020. J Pediatr Gastroenterol Nutr 2020;70(1):141-156.
- EBM France : diarrhée chronique
- Chapman T P, Chen L Y, Leaver L. Investigating young adults with chronic diarrhoea in primary care BMJ 2015; 350 :h573
- RecoMédicale : diarrhée chronique
- Grillot J. et al. Conduite à tenir pratique pour l’exploration d’une malabsorption, d’une maldigestion, et d’une entéropathie exsudative
- Biesiekierski, Jessica R et al. Non-coeliac gluten sensitivity. The Lancet, Volume 406, Issue 10518, 2494 - 2508