Take the Tummy Trouble Quiz Digestive Disease Myths Slideshow Pictures Heartburn? Foods to Eat, Foods to Avoid Slideshow

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Gastroenteritis Diagnosis

Gastroenteritis is often self-limiting, and the care is supportive to control symptoms and prevent dehydration. Tests may not be needed.

If the symptoms persist for a prolonged period of time, the health care practitioner may consider blood and stool tests to determine the cause of the vomiting and diarrhea.

Patient History and Physical Examination

Taking a thorough patient history and physical examination is very helpful in accessing the diagnosis.

Questions asked by the health care practitioner may ask include

1. Have any other family members or friends had had similar exposure or symptoms?
   
   
2. What is the duration, frequency, and description of the patient's bowel movements, and is vomiting present?
   
   
3. Can the patient is tolerate any fluids by mouth?

These questions help determine the potential risk of dehydration and may also include asking questions about the amount and frequency of urination, weight loss, lightheadedness, and fainting (syncope).

Other information in the medical history that may be helpful in the diagnosis of gastroenteritis include:

• Travel history: Travel may suggest E. coli bacterial infection or a parasite infection from something the patient ate or drank. Norovirus infections tend to occur when many people are confined to a close space (for example, cruise ship).
  
  
• Exposure to poisons or other irritants: Swimming in contaminated water or drinking from suspicious fresh water such as mountain streams or wells may indicate infection with Giardia - an organism found in water that causes diarrhea.
  
  
• Diet change, food preparation habits, and storage: When the disease occurs following exposure to undercooked or improperly stored or prepared food (for example foods at picnics and BBQs that should be refrigerated to avoid contamination), food poisoning must be considered. In general, symptoms caused by bacteria or their toxins will become apparent after the following amount of time:
  
  
  • Staphylococcus aureus in 2 to 6 hours
    
    
  • Clostridium 8 to 10 hours
    
    
  • Salmonella in 12 to 72 hours
    
    
• Medications: If the patient has used antibiotics recently, they may have antibiotic-associated irritation of the gastrointestinal tract, caused by clostridium difficile infection.

Physical examination will explore the reasons for symptoms that may not be related to infection. If there are specific tender areas in the abdomen, the health care practitioner may want to determine if the patient has appendicitis, gallbladder disease, pancreatitis, diverticulitis, or other conditions that may be the cause of the patient's symptoms.

Other noninfectious gastrointestinal diseases such as Crohn's disease, ulcerative colitis, or microscopic colitis also must be considered. The health care practitioner will feel the abdomen for masses. A rectal examination may be considered, in which the physician inspects the anus for any abnormalities and then inserts a finger in  the rectum to feel for any masses. Stool obtained during this test may be tested for the presence of blood.

The health care practitioner may perform other laboratory tests, including complete blood count (CBC), electrolytes, and kidney function tests. Stool samples may collected and tested for blood or different types of infection.