Folinic acid, fluorouracil and oxaliplatin (FOLFOX) can cause bruising and bleeding. https://www.cancerresearchuk.org/about-cancer/treatment/drugs/folfox
"This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae). Less commonly you might also bleed from other areas of the body for other reasons. For instance, some people might notice their poo is quite dark or they might pass fresh blood."

@lmhgator80, did your husband tell his cancer team about the bleeding, both the rectal bleeding and the nosebleeds? Has it stopped?