Colonoscopy & gastroscopy tomorrow morning

[Mimosita]

Hello, I'm new here.
On Friday morning, I will have a long colonoscopy and a gastroscopy. I have been having pain in right upper quadrant (liver?) since April--it's getting worse every day--, in my stomach, back and bowels (pinching-type pain on ascending and descending colon). I also have bright blood in my stool, I oscillate between severe constipation and mild diarrhoea. Ultrasound and CT-scan revealed nothing, no gallstones, no lesions.
Wondering if I could have celiac disease. Would a biopsy of my duodenum show it if I had it? I've been eating lots of gluten lately to make sure it would show up if the doctor tests me for that via a biopsy.
I've also recently developed what seems to be dermatitis herpetiformis close to my mouth. It comes and goes. I used to have a lot of those little pimples behind both my knees a few years ago. They came and went for a few years. Not itchy, though. Could that point to celiac? And my acne is just out of control (I'm 47!). Oh, and I also have joint pain and very dry eyes.
OK, that's it for now, but I could go on and on with my numerous symptoms!
Thank you in advance for your feedback,
Mims
PS: Any advice for my dreaded endoscopies?

[Mimosita]

Thanks for the reassurance!
Mims

[cnoevl21]

They should be able to tell if you at least have a gluten intolerance with a blood test. But yes, the biopsy will be able to show if you have celiac or not.

Neither test is really that bad. I've had them both done and didnt feel any pain afterwards. At worst you'll have soar throat from the endoscopy, and may have some pain from where they biopsy, but nothing severe.