Thanks for asking the query,
, bad breath occurs due to poor oral hygiene
maintainenece resulting in plague and food debris accumulation, nutritional deficienecies, immunological disorders, faulty appliances, hormonal imbalance.
I would suggest you to visit the Dentist
and get a checkup done.
Take an OPG radiograph which will give entire picture of gums, bone loss and wisdom tooth.
Go for symptomatic treatment of complete mouth scaling and polishing.
Take multivitamin tablets.
Include vitaminC, vitB12 containing food in your diet like lemon, oranges.
As you have mentioned you have GIT problems get a checkup done by a Gasteroenterologist.
Also check your menstural cycle, blood sugar level to know whether you are diabetic or not.
You might be having Pericoronitis
around the wisdom tooth,
Get checkup done and if needed get the tooth extracted.
Maintain a good oral hygiene.
Hope this helps out.