Tracey T asked:
He does brush his teeth …could it be coming from his stomach?
He does see a dentist regularly and it isn’t comming from his mouth…could it be coming from his stomach? what will help?

He could have gum disease. Take him to the Dentist.
He might have allergies.
Diet can have something to do with it. You may want to talk with his dentist, he could have gum issues. There are many rinses that could help, but you didn’t state his age so make sure you talk with a dentist first.
My daughters breath used to smell like fish all the time when she was a few months old, and it would drive me nuts, I took her to the doctor a couple of times and he could never give me an explanation, it did go away eventually but I would have to say it was not until she was over a year old. She had a small portion of her intestine removed when she was just a few weeks old so we figured it had something to do with it.
There are several possibilities.
It could be is stomach.
He could have a sinus infection
He could have an infection in his gums.
The best thing to do is have a doctor or dentist take a look.
tounge scrappers really help before you brush