Hello dear  Amir , hi
Warm  welcome to Healthcaremagic.com
I have evaluated your query for  your  father in details  .
*  There are many more reasons for the stomach pain as  
gastritis ,     
duodenitis , ulcer , inflammatory  lesions , tumors  ,  others .
*  Need  assessment  with all details  of  symptoms  , study of reports done
    till date  to  decide  the  further  line  of  management .
*  The raised BP and  pulse  are  reflex  physiological  phenomenon  due  to
     intensity  of  the  pain itself .
Hope this clears your doubt .
Wishing   him   fine recovery .
Welcome for any further  guidance .
Regards  .