For treatment of GERD, dexlansoprazole is effective and for functional chest pain, nonspecific adenosine antagonist, theophylline is proven to improve symptoms in patient with hypersensitive esophagus. A selective serotonin reuptake inhibitor (SSRI) is also effective for functional chest pain , however it is not known if theophylline is more effective than any other SSRIs.It is unknown about the response rates based on the guided therapy approach compared to the empirical PPI therapy.