2 Year Old Vomiting Mucus. Viral gastroenteritis is an infection that can cause diarrhea and vomiting. Symptoms of seasonal allergies include itchy, watery eyes, runny nose, cough and congestion, sneezing and.

Symptoms are the same as stomach infection viz. Symptoms of seasonal allergies include itchy, watery eyes, runny nose, cough and congestion, sneezing and. The stomach flu or other intestinal illness is the most likely culprit.