This is just something my husband has suggested but i don't know if it's possible. I have had digestive issues for 7 months but I never had any blood with any BM or anything. I went for a colonoscopy in end of April early May and a few days after was the first time I noticed blood when I wiped. Is that just coincidence or is it possible that during the colonoscopy they could have caused a tear?

Hi MONI07
Yes, it is possible for colonoscopy to cause a fissure. The anus is already usually pretty stressed from having had to do the cleaning out process with all that diarrhea and then the introduction of the scope combined with the movement and advancement thorough the anal canal to go deeper into the colon, followed by the withdrawal of the scope... well, it's all a lot of wear and "tear" on the anal area.

Yes. jr2 has explained it pretty well.