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

Antibiotic Treatment of Acute Diarrhea

In this article, we will discuss the Antibiotic Treatment of Acute Diarrhea. So, let’s get started.

Antibiotic Treatment of Acute Diarrhea

Empirical antibiotic therapy in bacterial diarrhea is controversial and generally not required in patients with mild or resolving disease but should be considered in patients with Shigellosis, traveler’s diarrhea, pseudomembranous colitis, cholera, food poisoning, and immunocompromised patients, etc. Empiric treatment with fluoroquinolones e.g. ciprofloxacin 500 mg, ofloxacin 400 mg twice daily is recommended in patients with fever, tenesmus or blood stools. The treatment is revised after culture and sensitivity reports. Only 5-10% of patients with diarrhea require specific antibiotic therapy, below is the list that specifies some organism and the associated choice of antibiotic.

  • Shigella and E.coli: Quinolones (norfloxacin 400 mg BID or ciprofloxacin 500 mg BID for 5 days)
  • Traveler’s diarrhea: Rifaximin 200 mg thrice a day for 3 days.
  • Cholera (Vibrio cholerae): Tetracycline
  • C.difficile: Vancomycin (250-500 mg QID for 7-10 days)
  • Campylobacter: Erythromycin 250-500 mg QID for 5 days or Azithromycin 500 mg OD for 5 days
  • Yersinia: Tetracycline 1-2 g/day for 7 days
  • Giardia: Metronidazole 200-400 mg TID for 7 days
  • E.histolytica: Metronidazole (400-800 mg TID for 5-7 days) or Tinidazole 600 mg BID for 5-7 days or Ornidazole 500 mg BID.

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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