Whether or not respondent Abalos’ illness is compensable is essentially a factual issue.  Yet the Court can and will be justified in looking into it considering the conflicting views of the NLRC and the CA.[17]     There is no question as to what respondent Abalos was sick of.  He was sick of cholecystolithiasis or gallstone.  It does not develop overnight.  It is caused by stone formation in the gallbladder that blocks the tube leading out of the gallbladder, causing bile to build up, resulting in gallbladder inflammation.  These gallstones are solid accumulations of the components of bile, particularly cholesterol, bile pigments, and calcium.[18]  The formation of gallbladder stones take months, if not years, to build up.    According to the NLRC, medical reports show that gallstone relates to one’s weight or diet and in some instances may be a genetic predisposition.  It is not one of those enumerated as compensable diseases in the Revised Standard Terms and Conditions Governing the Employment of Filipino Seafarers on Board OceanGoing Vessels that covered Abalos’ employment.  The NLRC denied him disability benefits and sickness allowance for this reason.       The CA held, however, that Abalos’ diet or sustenance on board the vessel had presumably caused or contributed to his illness for he had no choice but eat ship food.  Consequently, although his gallstone is not a compensable illness under his employment contract, it can be said that his illness was either work-related or reasonably connected with his work.    But, since cholecystolithiasis or gallstone has been excluded as a compensable illness under the applicable standard contract for Filipino seafarers that binds both respondent Abalos and the vessel’s foreign owner, it was an error for the CA to treat Abalos’ illness as “work-related” and, therefore, compensable.  The standard contract precisely did not consider gallstone as compensable illness because the parties agreed, presumably based on medical science, that such affliction is not caused by working on board ocean-going vessels.