Of all the medical history conditions included in this
survey, only gastrointestinal tract disorders and chronic
sinusitis were significantly associated with self-reported oral
malodor in regression analysis. Although gastrointestinal
tract disorders have been proposed as possible nonoral
causes of bad breath, and potentially associated with
Helicobacter pylori infection, the majority of evidence
suggests no direct associations. Chronic sinusitis has also
been reported by some authors as a possible etiologic factor in
oral malodor.