We say "have vomiting", without "a". Being an uncountable noun, the word "vomiting" doesn't take the indefinite article.
We say "have vomiting", without "a".
Does your child have vomiting or diarrhea?
Does your child have a vomiting or diarrhea?
Being an uncountable noun, the word "vomiting" doesn't take the indefinite article.
See your doctor if you have vomiting after eating.
Follow the same convention with the expressions "cause vomiting", "treat vomiting", "relieve vomiting", etc.
Some bacteria and food poisoning can cause vomiting.
Pregnant women in their first trimester may experience vomiting.
A partial list of other symptoms and diseases that do not take the indefinite article (a/an):
