Hi Conorconan1, welcome to healingwell! You have found a wonderful place for advise, everyone on here is great and very knowledgeable. It took me many tests to finally be dx. My ct scan was what finally gave them enough evidence of inflammation and narrowing. The colonoscopy he could not get up far enough and thru the ileocecal valve to see and the endoscopy could not go down far enough. All of my problems were in my terminal ileum area (where the large bowel meets the small bowel). But the ct scan showed the existing diseast.
Again the same as you, had very painful bleeding fissures and that did not trigger them to think crohn's. That was a few years before being dx. But hopefully, they will be successful and find you some answers with the colonoscopy. The prep is the worst and spending so much time on the toilet afterwards. How can sooo much liquid come out of one's body!!!!!! But the actual scope is a snap because you will be sedated and usually don't remember a thing.
One of the lovely ladies on here has educated me immensely with the use of extra virgin olive oil. It can be used for so many ailments and she is so right. Try applying a bit of this on your "bottom" to help with the soreness and how raw it can feel after the prep and going to the bathroom so many times. It really helps. Also you can try baby diaper cream (zinc oxide) works good too.
Try looking up some of the threads on here in the search site and you can read up on some of the diets and foods to avoid regarding your bloody D. Keep in mind everyone on here is different and what works for some might not for others. Good luck and keep us posted.