Editing Gastroenteritis (section)

==Diagnosis==
Gastroenteritis is typically diagnosed clinically, based on a person's signs and symptoms.<ref name=Eck2011/> Determining the exact cause is usually not needed as it does not alter the management of the condition.<ref name=Web09/>

However, [[stool culture]]s should be performed in those with blood in the stool, those who might have been exposed to [[food poisoning]], and those who have recently traveled to the developing world.<ref name=Webb2005/> It may also be appropriate in children younger than 5, old people, and those with poor immune function.<ref name="IDSA2017">{{cite journal|last1=Shane|first1=Andi L|last2=Mody|first2=Rajal K|last3=Crump|first3=John A|last4=Tarr|first4=Phillip I|last5=Steiner|first5=Theodore S|last6=Kotloff|first6=Karen|last7=Langley|first7=Joanne M|last8=Wanke|first8=Christine|last9=Warren|first9=Cirle Alcantara|last10=Cheng|first10=Allen C|last11=Cantey|first11=Joseph|last12=Pickering|first12=Larry K|title=2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea|journal=Clinical Infectious Diseases|date=19 October 2017|doi=10.1093/cid/cix669|pmid=29053792|pmc=5850553|volume=65|issue=12|pages=e45–e80}}</ref> Diagnostic testing may also be done for surveillance.<ref name=Eck2011/> As [[hypoglycemia]] occurs in approximately 10% of infants and young children, measuring serum [[glucose]] in this population is recommended.<ref name=Tint10/> [[Electrolytes]] and [[creatinine|kidney function]] should also be checked when there is a concern about severe dehydration.<ref name=Webb2005/>

===Dehydration===
A determination of whether or not the person has [[dehydration]] is an important part of the assessment, with dehydration typically divided into mild (3–5%), moderate (6–9%), and severe (≥10%) cases.<ref name=EBMED2010/> In children, the most accurate signs of moderate or severe dehydration are a prolonged [[capillary refill]], poor [[skin turgor]], and abnormal breathing.<ref name=Tint10/><ref>{{cite journal|last=Steiner|first=MJ |author2=DeWalt, DA |author3-link=Julie Story Byerley |author3=Byerley JS|title=Is this child dehydrated?|journal=JAMA: The Journal of the American Medical Association|date=9 June 2004 |volume=291|issue=22|pages=2746–54|pmid=15187057|doi=10.1001/jama.291.22.2746}}</ref> Other useful findings (when used in combination) include sunken eyes, decreased activity, a lack of tears, and a dry mouth.<ref name=EBMED2010/> A normal urinary output and oral fluid intake is reassuring.<ref name=Tint10/> Laboratory testing is of little clinical benefit in determining the degree of dehydration.<ref name=EBMED2010/> Thus the use of urine testing or ultrasounds is generally not needed.<ref>{{cite journal|last1=Freedman|first1=SB|last2=Vandermeer|first2=B|last3=Milne|first3=A|last4=Hartling|first4=L|title=Diagnosing clinically significant dehydration in children with acute gastroenteritis using noninvasive methods: a meta-analysis|journal=The Journal of Pediatrics|date=April 2015|volume=166|issue=4|pages=908–916.e6|pmid=25641247|doi=10.1016/j.jpeds.2014.12.029|s2cid=29662891 }}</ref>

===Differential diagnosis===
Other potential causes of signs and symptoms that mimic those seen in gastroenteritis that need to be ruled out include [[appendicitis]], [[volvulus]], [[inflammatory bowel disease]], [[urinary tract infection]]s, and [[diabetes mellitus]].<ref name=Webb2005/> [[Pancreatic insufficiency]], [[short bowel syndrome]], [[Whipple's disease]], [[coeliac disease]], and [[laxative]] abuse should also be considered.<ref name="Oxford">{{cite book|editor1=Warrell D.A. |editor2=Cox T.M. |editor3=Firth J.D. |editor4=Benz E.J. |title=The Oxford Textbook of Medicine |publisher=Oxford University Press |year=2003 |isbn=978-0-19-262922-7 |edition=4th |url=http://otm.oxfordmedicine.com/ |url-status=dead |archive-url=https://web.archive.org/web/20120321002102/http://otm.oxfordmedicine.com/ |archive-date=2012-03-21 }}</ref> The differential diagnosis can be complicated somewhat if the person exhibits ''only'' vomiting or diarrhea (rather than both).<ref name=EBMED2010/>

Appendicitis may present with vomiting, abdominal pain, and a small amount of diarrhea in up to 33% of cases.<ref name=EBMED2010/> This is in contrast to the large amount of diarrhea that is typical of gastroenteritis.<ref name=EBMED2010/> [[Lower respiratory tract infection|Infections of the lungs]] or urinary tract in children may also cause vomiting or diarrhea.<ref name=EBMED2010/> Classical [[diabetic ketoacidosis]] (DKA) presents with abdominal pain, nausea, and vomiting, but without diarrhea.<ref name=EBMED2010/> One study found that 17% of children with DKA were initially diagnosed as having gastroenteritis.<ref name=EBMED2010/>