Clinical Features and Investigations of Acute Diarrhea

In this article, we will discuss the Clinical Features and Investigations of Acute Diarrhea. So, let’s get started.

Signs and Symptoms

  • Nausea, vomiting
  • Abdominal pain
  • Fever
  • Watery stools
  • Blood in the stool (hematochezia)
  • Excessive thirst

Signs of dehydration may be present

  • Patient irritable
  • Weak pulse, low BP
  • Depressed fontanelle
  • Dry pinched facies
  • Sunken eyeballs
  • Dryness of mouth, tongue, mucous membrane
  • Loss of skin turgor


  • Stool examination for leukocytes, ova, parasites, blood and pus cells, etc
  • Stool for fecal lactiferin: It is a sensitive marker of fecal leukocytes, indicates inflammatory diarrhea. It is estimated by ELISA and latex agglutination test
  • Stool immunoassay for bacterial toxins (c.difficile), viral antigen (rota virus) and protozoal antigens (Giardia, E.histolytica)
  • Stool culture for isolation of the infective agent, i.e. enterohemorrhagic and other types of E.coli, Vibrio species and Versinia
  • Complete hemogram
  • Blood biochemistry, e.g. urea, creatinine, electrolytes
  • Blood culture
  • Sigmoidoscopy with biopsies and upper endoscopy with duodenal aspirates and biopsy if indicated
  • Abdominal X-ray or CT scan

Causes of Acute Diarrhea

In this article, we will discuss various Causes of Acute Diarrhea. So, let’s get started.


Infective cause (90% cases) include:

  • Virus e.g. rotavirus, norovirus, cytomegalovirus, viral hepatitis.
  • Bacterial e.g. Enterotoxin-induced i.e. Staphylococcus aureus, B.cereus, C. perfringens, E.coli, V.cholera. Cytotoxin-induced i.e. E.coli, toxic shock syndrome. Mucosal invasion i.e. Shigella, Salmonella, Campylobacter, Yersinia, Traveller’s diarrhea.
  • Parasitic i.e. Giardia, E.histolytica, Cryptosporidium, Cyclophora.

Non-infective causes (10% cases) include:

  • Drugs e.g. laxative, digitalis, ampicillin.
  • Ischemic colitis
  • Pseudomembranous colitis
  • Diverticulitis
  • Graft vs host disease
  • Toxin-induced diarrhea i.e. organophosphorus, insecticide, amanita, mushroom, and seafood.
  • Food allergy/intolerance
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