your symptoms appear to be very troublesome and confusing. they appear genuine hence i request you to get investigated. to summarize, you are having anemia, low blood pressure, stomach fullness,
abdominal pain, bleeding from rectum, knee and hip joint pain with a strong family history of cancer. i want you to undergo a
CT scan of the abdomen with contrast, a chest x ray, a
complete blood count, CEA and CA19-9, ESR, CRP,
rheumatoid factor, ANA, ANCA And Clotting profile. meanwhile you can take
pantoprazole tablets 40mg twice daily before food, and pain medications for your knee problems.
to explain if you have anemia you are either deficient in iron or loosing blood from somewhere in the stomach or intestines .. thats why the pain and bloody stools. this may also be due to abnormal clotting factors which lead to bleeding in the gastrointestinal system and also maybe in your knees.