I have gas build up in my body. the gas is not causing any pain or discomfort but i has severe bad breath which smells like excrement for 2 months now?

Periodontal disease: Check with your dentist, a periodontal consultation may be in order, in addition to a visit to your MD.

Bad breath: In the majority of cases, the cause of bad breath, or halitosis, is the product of bacteria in the mouth and gum disease. The proper diagnosis is the key to a successful treatment. See your dentist for Halimeter test, diagnosis and bad breath treatment that depends on its cause. Good luck.