What Causes Rectal Bleeding With No Bowel Movements?

Question: I recently had an admission and it was noted that I continuously had an elevated white blood count. I also had rectal bleeding and no bowel movements for three days. I feel that I have some worm like type things coming out of the top of my head. I have had an outbreak of sores on my forehead and have been accused of picking these soars which is not so. I have not been able to have a Pet Scan yet but have had numerous other test which all showed negative and no one believes what I am saying. No one has checked my skull but I did have what they call a CT Scan of my skin which was negative too. My potassium levels dropped and I as dehydrated. I was treated two years ago for cellulitis and now have this problem. Trying to explain this in the hospital along with pictures I had taken of myself to show the doctors lead them to believe and state that I needed a psych doctor. D/C was listed as Rectal bleed, possible ulcerative colitis. I had no bowel problems until the rectal bleeding of three days. One doctor stated that if the biopsy results are positive of for ulcerated colitis, given that the areas of skin rashes, tend to be slightly ulcerative in nature, pyoderma gangerenosum would be on the differential. I am now home still feeling this awful crawling feeling in the top of my head. Now, I have to prove that I am not psychotic with parasitosis. I was employed by the Dept. of Veterans Affairs for thirty one years as an Operational Manager in the Health Information Management Section. Now I find myself in this position and I need to prove that I do have something more going on in my body. All test so far according to what I have been told are negative....so no one believes me. I am now in the process of trying to see if I can have a Pet Scan but so far no luck. I need to prove this is not in my mind. I have been told I had acute rectal bleed and listed as have acute Abdominal pain. Do you have an suggestions of what I can do to prove my medical issues? I am trying to see an Infectious Disease Doctor. Am I on the right track? Any assistance would be greatly appreciate. Thank you.

Am I correct in thinking that this would be considered an Infectious Control matter? I never had a Pet Scan in all the time I have had this problem. This is the correct type of test that should prove what I am saying right? I am sorry for needing reassurance but I have had such problems getting assistance all this time.
Thank you for your timely response.