Symptoms of Gastroenteritis
Gastroenteritis typically presents with acute onset of diarrhea and vomiting, often accompanied by nausea, abdominal pain, and fever, with symptoms usually beginning abruptly and lasting 1-7 days. 1, 2
Core Gastrointestinal Symptoms
- Diarrhea is the hallmark symptom, typically watery and non-bloody, with 10-20 bowel movements per day in severe cases 1, 2
- Vomiting occurs in 80-90% of cases, particularly prominent in viral gastroenteritis, and usually lasts less than 24 hours 1, 2
- Nausea is a prominent feature, especially with Norwalk-like viruses 1
- Abdominal pain and cramping are common, occurring in most cases 1
Systemic Symptoms
- Fever is present in many cases, though typically low-grade; higher temperatures suggest bacterial etiology rather than viral 1
- Headache occurs in 25-50% of affected persons 1
- Myalgias and body aches are reported in 25-50% of cases 1
- Chills may accompany the illness 1
Clinical Presentation by Pathogen
- Rotavirus gastroenteritis begins with acute onset of fever and vomiting, followed 24-48 hours later by watery diarrhea, frequently associated with upper respiratory symptoms 2, 3
- Norovirus infections are characterized by sudden onset with prominent nausea and vomiting, non-bloody diarrhea, and abdominal cramps, typically lasting 12-60 hours 1
- Bacterial gastroenteritis (Shigella, Salmonella, Campylobacter) presents with inflammatory features including fever, abdominal pain, and bloody stools 1
Age-Related Symptom Variations
- In children, vomiting is relatively more prevalent, while adults experience diarrhea more frequently 1
- Elderly persons often report persistence of constitutional symptoms for up to several weeks after acute illness 1
Signs of Dehydration (Critical Complication)
- Thirst, tachycardia, and orthostatic changes indicate volume depletion 1
- Decreased urination, lethargy, and decreased skin turgor are warning signs 1
- Dry mucous membranes and altered sensorium occur with progressive dehydration 1
Typical Duration and Course
- Incubation period ranges from 12-48 hours for most viral causes 1
- Symptom duration is typically 1-3 days for viral gastroenteritis, though can extend to 4-6 days in young children, elderly persons, and hospitalized patients 1, 2
- Rotavirus illness commonly lasts 5-8 days 3
Important Clinical Caveats
Bloody stools with fever and systemic toxicity suggest bacterial infection (particularly Shiga toxin-producing E. coli, Shigella, or Salmonella) rather than typical viral gastroenteritis and warrant immediate medical evaluation 1. Severe abdominal pain that is disproportionate to examination findings may indicate complications requiring urgent assessment 1. Asymptomatic shedding and mild cases without all classic symptoms are common, particularly with norovirus 1, 4.