The evaluation of cholera begins with a medical history and physical examination.

Physical findings in someone with cholera may include:

• Fever
• Signs of dehydration

Signs of dehydration include:

• Pale, dry skin
• Dry eyes
• Dry mouth
• Decreased urination
• Sunken eyes
• Sunken fontanelle in infants
• Rapid pulse
• Low blood pressure when standing
• Confusion
• Lethargy:
• A condition of excessive sleepiness or drowsiness.

The diagnosis of bacterial gastroenteritis due to cholera must be confirmed through testing. A stool specimen can be cultured for a suspected bacterial infection. Stools may be tested for C. difficile toxin: a test specifically used to diagnose pseudomembranous colitis. A stool examination for ova and parasites can be helpful in detecting parasitic infections.

A stool culture can detect:

• Cholera (Vibrio cholerae)
• Shigella infection
• Campylobacter enteritis
• Cryptosporidium enterocolitis
• Giardiasis
• Pseudomembranous colitis:
• Clostridium difficile
• Salmonella gastroenteritis
• Traveler's diarrhea due to bacterial infection
• E. coli

Tests that may be used to evaluate cholera include:

• Complete blood count
• Liver profile
• Kidney profile