A 2-year-old with acute onset of vomiting and diarrhea 24 hours ago. Which is the most likely cause of the symptoms?

• A. Bacterial Gastroenteritis
• B. Viral Illness
• C. Appendicitis
• D. Intussusception

Answer: (B)

Viral gastroenteritis is the most common cause of acute vomiting and diarrhea in toddlers. In young children, viruses such as rotavirus or norovirus often cause a sudden onset of vomiting followed by watery, nonbloody diarrhea that lasts a few days. This pattern is typical and explains why a viral illness is the best answer for a 2-year-old with rapid onset and short duration of these symptoms.

Bacterial gastroenteritis can cause vomiting and diarrhea as well, but it usually comes with higher fever, abdominal cramps, and often bloody or mucous-containing stools, and its onset may be linked to a specific food exposure. Appendicitis presents with progressing abdominal pain that starts around the periumbilical area and localizes to the right lower quadrant, often with fever and poor appetite. Intussusception tends to show intermittent, severe colicky pain with episodes of drawing up the legs, lethargy, and sometimes “currant jelly” stools, which is a different presentation from straightforward vomiting and diarrhea.

The key takeaway is that rapid onset of vomiting with subsequent nonbloody diarrhea in a toddler most commonly points to a viral infection, with supportive care focusing on fluids and comfort while watching for signs of dehydration.