Need advice on my medical condition

So this is an update on my last post and it is to see if anyone has gone through anything similar. I am still losing hair and sleeping alot (15 hours+ a day) but my doctor ran lab work and it all came out fine ( my calcium was a little high but nothing to be concerned with). So last week I got a stabbing brace yourself kind of pain in my rectum. The pain would last about 15min at a time then I would pass out. That happened all day then at 11pm that night it happened again but I passed out then started seizing and when I came to I couldn't remember anything. So my husband took me to the ER. The ER told me I didn't have had a heart attack and that I came in too late to tell if it was a stroke and to just go see my gastroenterologist as soon as I could get in. So when I went to the GI doctor she was so concerned that I haven't been pooping every day and that when I did pooping ( I poop anywhere form every 2 weeks to once a month) lots of blood would come out until I closed my anus. My poop is also black. I have bad heartburn it causes pain in my chest ribs and back. I also lost all my appetite I am forcing myself to eat dinner everyday even though I'm not hungry. I will randomly gain 20lbs then loose it with in a week or so. My gastroenterologist wants me to have a Cat scan from my chest all the way down to my pelvis. She always wants me to have a colonoscopy and EGD. Has this ever happened to anyone and what should I do?