Thank you. About two months ago, I had a bad fall. I suffered a pelvic fracture. ((I use a wheelchair with distance, and when very tired. I had the wheelchair to the side, but not in back of me). Since then, every time I do some activity, like cleaning my pet s litter box, I have constipation with very dark stools, and residue that looks like bleeding. Hot temperatures, over 90 degrees F, also causes the problem. It clears up in two days, with rest. I appreciate your assistance!