Horrendous breath may indicate tooth decay which is often caused by a mixture of bacteria including anaerobic (bacteria that don t need oxygen to grow). These latter bacteria are often the cause of a fecal odor in the mouth. I would see the dentist, but would also try flossing twice daily and using an a becterial killing mouthwash (such as Scope or Listerine). Tongue rakes can also be used to remove coatings from the tongue that will also cause bad breath prior to using mouthwash. Other concurrent problems such as dry mouth from Sjogren s syndrome may also cause dry mouth. In your case, gastroesophageal reflux .... where stomach contents move backwards up the esophagus can also lead to upper abdominal pain and bad breath and tooth decay from acid erosion of your teeth. I am not sure what direction your doctor is taking in your care. Erythromycins in low doses can increase gastric motility, but Deflu is typically for symptomatic cold relief. Hope this helps.