Gastroenteritis test

Submitted by Thiruvelan on 28th Apr 2013 | Last updated 4 August 2014

Gastroenteritis diagnosis begins with gastroenteritis symptoms. Prefer stool cultures in case of bloody stool. Assess the degree of dehydration.

Gastroenteritis diagnosis

Gastroenteritis tests to examine stool samples are to identify the microbe causing the sickness. A stool culture may require finding whether diarrheas are causing the problem. If symptoms have fever, bloody stool and diarrhea continue for two weeks or more, stool examination for Clostridium difficile may be advisable along with cultures for bacteria, including Salmonella, Shigella, Campylobacter and Enterotoxic Escherichia coli. Microscopy for parasites, ova and cysts may also be helpful.

Assess dehydration

Dehydration is a common diarrhea complication. Some of the signs of dehydration include dry or sticky mouth, lethargy or coma (in case of severe dehydration), low-pressure, low or no urine output, sunken soft spots in the top of an infant's head, no tears, and sunken-eyes.
A child with a significant dehydration can assess by:

  • Prolonged capillary refill – is the rate at which blood refills empty capillaries. It is assessing by pressing the soft pad of a finger or toe until it turns white, and taking note, the time needed for the color to return once pressure released.
  • Poor skin turgor is the skins delayed ability to change shape and return to normal (lack of elasticity). To assess skin turgor, your doctor grasps the skin at the hand backside, lower arm, or abdomen between two fingers and tent up. Hold it for few seconds then released; healthy hydrated skin rapidly returns to its original position. However, dehydrated skin has decreased turgor returns slowly to its normal position.

Other useful dehydration symptoms include sunken eyes, decreased activity, a lack of tears, and a dry mouth. Laboratory testing is of little clinical benefit in determining the degree of dehydration.

Differential diagnosis

Symptoms that mimic the gastroenteritis symptoms need to rule out; some of these conditions include:

  • Appendicitis symptoms are vomiting, abdominal pain, and a small amount of diarrhea. However, in the case of gastroenteritis, there is a large amount of diarrhea.
  • Infections of the lungs or urinary tract in children may also cause vomiting or diarrhea.
  • Diabetic ketoacidosis (DKA) symptoms are abdominal pain, nausea, and vomiting, but without diarrhea. One study found that 17% of children with DKA have initially diagnosed as gastroenteritis.
  • Inflammatory bowel disease symptoms are vomiting, and diarrhea. Additionally, it has rectal bleeding with anemia. Your doctor would perform a rectal or abdominal examination to exclude the possibilities of inflammatory bowel disease (e.g., Crohn’s disease) and pelvic abscesses (pockets of pus).
  • Other conditions with similar symptoms are pancreatic insufficiency, short bowel syndrome, Whipple’s disease, coeliac disease, and laxative abuse.