The anus is in the outside and about
an inch or slightly more internally before it becomes the rectum.
Some UCers have anal issues, but not with UC specifically. CDers, such as pb4 have perianal, rectal and colon involvement which is part of that type of CD. I have a friend with fistulising CD, so primarily perianal involvement with a patch in the colon.
I don't think you should try to diagnose yourself, but you should make sure you have the pertinent testing to get a diagnosis. A colonoscopy is the first tool, with biopsies if you have inflammation. Stool testing should also be part of the process to rule out any invaders. Blood testing should be done to check out inflammation, markers, blood levels, etc.
Yes, diarrhea wouldn't be caused by hemmies as pointed out. Simple diagnosis as such is an insult by doctors. I had that thrown at me before I saw the GI...it was a relief to finally know what was going on.
You do need to get on medications if you have hemmies or fissures to help heal those. Push for it after your scope, or ask the doc for a prescription for the nurse to give you after the scope if you're "out of it".
External tags can be a result of a fissure. I have one, and I don't have CD.
Is a GI doing the scope or the anorectal surgeon?
What prep are you using tomorrow?
Hang tough...it's really stressful until a diagnosis...I truly hope you don't have either and that simple persistent treatment will be all you need.
Welcome to the forum! Keep us posted for sure.
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