Hello,
I have gone through your query and understand your concern.
I suspect refusal of foods and
tiredness could not be due to the Ladd's procedure which is done 4 weeks before.
Further he do not have any
fever or
abdominal pain or stool changes.
Thus nothing to worry.
It is usual in this age to refuse the foods and water.
He just had one episode of vomit and other than this all are fine.
This could be due to his unlike of the food given in breakfast.
Encourage him to take the foods what ever he like.
You have to worry only if he have any abdominal pain, fever, severe vomit, blood or watery stool.
if he have any of these, then he might need immediate medical care.
Hope this helps.
Please write back for further queries.
Wishing you good health.