My Elderly Father Age 90 Is Complaining Of Pain Around

My elderly father age 90 is complaining of pain around his navel and pains going across from side to side from that area. I was just wondering if this is something we should contact his GP about. No heart problems, suffers from prostate cancer and alzhiemers. Last check up with oncologist everything seemed to be ok not to return for visit in 6 months.