see also [[paediatric NGT#Approach to rehydration]], [[Blood in infant stool]] > **✱ Beware** “gastroenteritis” in a [[Vomiting]] patient without diarrhea. Although vomiting may precede diarrhoea in the first 24–48 hours of gastroenteritis, in a vomiting patient without diarrhoea, [[Diagnoses of exclusion|other causes]] must be considered. > [!important] **"Red Flag"** features of paediatric gastro: > - age <6 months > - high grade fever >40 > - bilious vomiting > - significant abdominal pain > - no diarrhea  > - blood in vomit or stool > - drowsiness/reduced level of consciousness > - CNS symptoms eg seizures (HUS) > - known high risk exposures # Oral rehydration Whenever possible, the enteral route (oral or nasogastric) should be used for rehydration > Aim for **10mL/kg/H of oral solution (eg Gastrolyte, pedialyte)**, can do apple juice 1:1 with H2O for short period (no electrolytes) > - cont breastfeeding > > If rehydration fails and child is ≥ 5% dehydrated, rapid or slow [[paediatric NGT|paeds NG fluids]] may be appropriate. would need IV if not tolerating NGT # When to give Abx Antibiotics should be reserved for: - treatment of enteritis-associated sepsis - specific bacterial pathogens in selected cases: - Salmonella typhi - non-typhoidal salmonella in patients under 3 months - immunocompromised - sepsis - severe Clostridium difficile infection # Who should get stool samples? Faecal testing in patients with acute diarrhoea is only appropriate when the results will inform management. Faecal testing, including for _Clostridioides difficile_, is recommended in: - patients presenting with bloody stools, moderate to severe disease, or with prolonged symptoms - immunocompromised patients; in addition to faecal microbiological testing for routine pathogens, request tests for parasites and viral pathogens - situations of public health importance (eg an outbreak, in residential aged-care facilities, food handlers); perform testing as directed by the local public health authorityz Traditional faecal microbiological testing—including bacterial culture, microscopy and antigen testing—continues to have an important role in the assessment of acute infectious diarrhoea, despite the relatively low yield in comparison to mPCR. A positive result is highly likely to be diagnostic, and, crucially, the resulting bacterial isolates enable antimicrobial susceptibility testing and epidemiological assessment. Culture-independent methods, including a number of commercially available mPCR assays, have recently become widely available. mPCR presents some significant advantages over traditional faecal testing, but there are also disadvantages. ## possible causes of diarrhoea - Campylobacter enteritis - Clostridioides difficile infection - Enterohaemorrhagic Escherichia coli enteritis - Salmonella enteritis - Shigella enteritis - Vibrio cholerae (Cholera) - Vibrio: Noncholera species - Yersinia enterocolitis - Cytomegalovirus (CMV) infection - Cryptosporidium species - Cyclospora cayetanensis - Cystoisospora (Isospora) belli - Microsporidia. ### Bloody vs non-bloody diarrhoea DDx table see: [Oxford handbook of tropical medicine - Acute diarrhoea with blood](x-devonthink-item://7D556ECD-D277-4122-943B-E1E4B6D2D556?page=267) > [!caption] Infective diarrhoea with blood = **dysentery** | Bloody diarrhea | Watery diarrhea | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | - campylobacter<br>- e histolytica<br>- Enterohemorrhagic E coli<br>- Enteroinvasive E coli<br>- Salmonella (non-typhoidal) enterocolitis<br>- shigella (bacillary dysentery)<br>- Yersinia enterocolitica<br>- CMV in [[Diarrhoea in HIV patients\|immunosuppressed]] patients | - C difficile<br>- C perfringens<br>- Enterotoxigenic E coli (travelers' diarrhoea)<br>- protozoa (giardia, cryptosporidium)<br>- v cholera <br>- viruses (rotavirus, norovirus, enteric adenovirus) | > [!caption]- Comments > ***Bloody causes*** > - Campylobacter ∝ [[Guillain-Barré syndrome|GBS]] > - e histolytica → protozoan, amebic dysentery, *liver abscess* > - Enterohaemorrhagic E coli (EHEC) O157:H7 can cause [[Haemolytic uraemic syndrome|HUS]], maes shiga-like toxin > - non-typhoidal salmonella not as severe, often a/w poultry and eggs > - Shigella also causes [[Haemolytic uraemic syndrome|HUS]] from shiga toxin in severe cases > > ***Watery causes*** > - C diff → causes pseudomembranous colitis. a/w abx. occasionally bloody diarrhoea > - C perfringens also causes gas gangrene > - Enterotoxigenic e coli → travelers' diarrhoea > - cholerae "rice-water diarrhoea"