Gastroenteritis refers to inflammation of the stomach and small or large intestines that produces symptoms such as diarrhea, vomiting and abdominal pain. The term is often called "stomach flu" or "stomach bug," though it is unrelated to the influenza virus. For a general definition see inflammation, and for related anatomy see stomach and intestines.
Causes and transmission
Most cases are caused by infectious agents. Viruses (for example, norovirus and rotavirus) are frequent culprits, while bacteria (such as certain strains of Escherichia coli, Salmonella, or Campylobacter) and parasites can also produce gastroenteritis. Infections spread by contaminated food or water, person-to-person contact, or contact with contaminated surfaces. Although commonly called "flu," gastroenteritis is not caused by the influenza pathogen—see influenza for the respiratory illness.
Symptoms and complications
Typical symptoms include:
- Watery diarrhea
- Nausea and vomiting
- Stomach cramps and abdominal discomfort
- Fever or malaise in some cases
Most healthy people recover within days, but serious dehydration is a primary concern, especially for infants, young children, older adults, and people with weakened immune systems. Severe or prolonged symptoms warrant medical evaluation.
Diagnosis and treatment
Diagnosis is usually clinical, based on history and symptoms. Laboratory tests—stool cultures, antigen or molecular assays—are used when the cause needs confirmation or when outbreaks occur. Treatment focuses on supportive care: oral rehydration to replace lost fluids and electrolytes, dietary adjustments, and rest. Antiemetic or antidiarrheal agents may be used selectively. Antibiotics are reserved for specific bacterial infections and are not appropriate for viral causes.
Prevention and public health
Prevention emphasizes hand hygiene, safe food handling, and clean water. Vaccines exist for some causes (for example, rotavirus vaccines for infants) and are part of routine immunization programs in many countries. During outbreaks, limiting exposure and surface disinfection reduce spread. For further reading about common symptoms and management see diarrhea, stomach pain, and common viral agents like viral causes and bacterial causes.
Notable distinction: The colloquial label "stomach flu" can cause confusion; gastroenteritis refers to gastrointestinal inflammation, whereas true influenza primarily affects the respiratory tract. Awareness of this difference helps guide prevention and treatment choices.