Gastroenteritis: Test and Diagnosis

Laboratory parameters of the 1st order – obligatory laboratory tests.

  • Laboratory parameters 1st order – obligatory laboratory tests.

    • Small blood count
    • Differential blood count
    • Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
    • Stool examination for enteropathogenic pathogens (not routine pathogen diagnostics); diagnostics only if (mod. according to):
      • Medical history
        • Relevant comorbidities (concomitant diseases).
        • Patients with immunosuppression
        • Patients who work in community settings or food processing institutions.
        • People with taken antibiotics within the last 3 months.
      • Hemorrhagic diarrhea (bloody diarrhea).
      • Appearance of diarrhea symptoms shortly after return from a stay abroad in patients with
        • Febrile and /or bloody diarrhea.
        • Diarrhea that lasts > 5 days
        • Severe clinical course (high stool frequency, significant dehydration/dehydration of the body (> 10% of body weight), “systemic inflammatory response syndrome” (SIRS)).

      Stool diagnostics: campylobacter, salmonella and shigella, and microscopic stool examination for amoebae and lamblia; if antibiotic therapy was given in the last three months, also for clostridia.

      • Symptomatology not improved even after 7 days.
      • Doubts exist about the diagnosis of gastroenteritis
      • Severe clinical picture (e.g., fever, dehydration, “systemic inflammatory response syndrome”/sepsis).
      • If a cluster is suspected, suggesting an epidemiological link.
      • Before initiation of antibiotic therapy
      • Ambulatory-acquired gastroenteritis:
        • 1-2 stool samples for campylobacter, salmonella, shigella and norovirus.
        • 3 consecutive (“successive”) stool samples if parasitosis (infection with parasites) is suspected.

Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.

  • Stool examination for enteropathogenic pathogens such as Campylobacter, Salmonella, Shigella, Yersinia, as well as Aeromonas, EHEC (enterohemorrhagic E. coli; EHEC symptoms: microangiopathic hemolytic anemia (anemia), thrombocytopenia (deficiency of platelets) and acute restriction of kidney function), Pseudomonas, Vibrio cholerae, Staphylococcus aureus, enteropathogenic E. coli (EPEC; dyspepsia coli) in children [if infection with Escherichia coli O157:H7 is detected, monitoring for hemolytic uremic syndrome is required!].
  • Antigen in the stool for enteropathogenic viruses such as adenoviruses, coxsackie, rotavirus and recently increasingly common noro virus (RNA detection in stool).
  • Stool examination
    • Fungi
    • Parasites and worm eggs (2-3 consecutive stool samples required).
  • Stool examination for blood
  • Malaria detection
  • Elastase in stool (pancreatic enzyme).
  • Lactose tolerance test for suspected lactose intolerance.
  • Small blood count and differential blood count
  • CRP
  • Electrolytes – sodium, potassium
  • Renal parameters – creatinine, urea
  • Pancreatic parameters – amylase, lipase
  • Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), gamma-glutamyl transferase (γ-GT, gamma-GT; GGT).
  • Allergen-specific IgE (food allergy).
  • Vasointestinal polypeptide (VIP).
  • Urine: 5-HIES (5-hydroxyindoleacetic acid due tocarcinoid diagnostics), porphyrins (due tometabolic diagnostics).
  • Serology: AK against amoebae, campylobacter, rotavirus, salmonella, shigella, yersinia.

Important notes on diagnostics in children

  • A blood test or pathogen detection in the stool are usually not necessary in mild to moderate acute diarrhea.
  • About 70% of all acute gastroenteritis in children are caused by viruses (noroviruses, rotaviruses and adenoviruses).
  • About 20% of children have bacterial pathogens (Campylobacter jejuni, Yersinia, Salmonella, Shigessen, pathogenic E. coli or Clostridium difficile) in the stool.
  • Attention.In about 5% of cases, parasites (cryptosporidia, Entamoeba histolytica, lamblia and others) are the cause of infectious intestinal disease.

Note: In bold pathogens to be tested for in case of community-acquired diarrheal disease. * E. coli strains: this includes the so-called ETEC = enterotoxic, EHEC = enterohemorrhagic, EIEC = enteroinvasive and EPEC = enteropathogenic E. coli strains. Notifiable in the sense of the Infection Protection Act:

  • The direct or indirect detection of “Campylobacter sp., enteropathogenic” is reportable according to the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection.
  • Direct detection of the pathogen (Norwalk-like virus) is reportable under the Infection Protection Act (IfSG). Notification requirement only for direct detection from stool.
  • Direct or indirect detection of rotavirus is reportable according to the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection.
  • Direct detection of “Salmonella Typhi/Salmonella Paratyphi” is reportable according to the Infection Protection Act (IfSG).
  • The direct or indirect detection of “Salmonella, other” is reportable under the Infection Protection Act, as far as the evidence indicates an acute infection.
  • The direct or indirect detection of “Shigella sp.” is reportable under the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection.
  • The direct or indirect detection of “Vibrio cholerae O 1 and O 139” is reportable under the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection.
  • The direct or indirect detection of “Yersinia enterocolitica, intestinal pathogen” is reportable under the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection.