I Had A Bowel Movement A Couple Of Days Ago

I had a bowel movement a couple of days ago and experienced a little blood in my stool and on the toilet paper. Since then I have been getting cramps in the pelvic floor region. The cramps and pain seem to get worse when I have gas and need to have a bowel movement. The gas and bowel movement itself isn't painful, but when I bear down, is when the pain hits. The cramps and pain seem to be coming higher up in the rectum area. There is no discomfort coming from the anal area and I have not experienced any more blood in my stool or on the toilet paper. I had a colonoscopy a few months ago (before experiencing this problem). The colonoscopy was normal. What can be causing the pain and cramping?