l have chronic bad breath but am very clean. l do not smoke or eat anything that might be deemed ''offensive''. l brush, floss, rinse and clean tongue.Long story short, went to dentist, he said my mouth was immaculate. Suggested ENT visit. Had extensive tests and was told my sinuses were clear and completely healthy. He suggested gastro Dr. Went there and was told no issues, maybe check back with dentist. l am at my wits end!l have tried every mouthwash on the market and l brush/floss a minimum of 3-4 times a day to no avail. What could it be? It is frustrating because l do not know who else to go to. Professionalappreciated

What do you mean ''not from mouth.''

Well, l kinda have the same issue but it is when l wake up my whole room smells--and it is not just like everyone who wakes up and has bad breath. (sorry it l grossed you out)

Maybe just let time pass it by???

Other causes of Bad breath are :
Gum desease, tonsilitis, maybe you have diabetes, Lungs or liver or kidney problems. Probably you are taking some medicines like anti depressant or high blood pressure tablet that cause bad breath.
l can suggest to have a general check up to the doctor , a blood test for kidney, liver, lungs, sugar level, etc.. because having bad breath means you have a medical condition or issue somewhere in your body.

have you tried lung specialist? The bad breath can come from lung infection.