Hello Angelica. I am very sorry to hear that your mom was diagnosed with Colon Cancer. My father has it as well and is using the same drug as your mom. The oncologist has told my dad that there is an alternative drug that they give in pill form if the patient cannot handle the oxaliplatin. I do not know the name of it but I am sure the oncologist will know.
As far as the anemia, have someone ask the oncologist if it is okay to put her on some type of multi vitamins with Iron. Either that or they should be able to give your mom an injection in the office that helps with the anemia.
Either way I hope your mom recovers and can handle the chemo since it IS the best choice.