I Am A Post Chemo/radiation Patient With Many Lingering Health

I am a post chemo/radiation patient with many lingering health problems and new allergies due to said treatments received.... the Autonomic Nueropathy, does not allow for my body to regulate my heart rate, blood pressure etc... unfortunaltely (sic) test have shown I have developed a severe intenstinal problem..."caverns, throughout my bowls", causing malnutrion, along with other issues due to my digestive system not being able to completly empty or absorb foods I consume. I also have Celiac Disease. My DR. (a great one) has prescribed "Amitiza 8 mcg caps 2 x's per day to treat this condition. In the hopes it will clean out my entire digestive tract enough for the "caverans" to heal. They become infected, then the infections spread throughout my body. Also need to make sure this medicene has no Wheat Rye or Barley in it....and scared of it throwing me into the roller coaster BP up's and downs I go through regularly anyway....plus the damage that the chemo did to my heart (it has recovered some). According to my Dr. if this condition does not get under control, I will be dead in about a year or longer. But if I take this medicene, it could kill me due to heart issues and BP rapid highs and lows.