You may lose menstruation during Stage 2 colon cancer, but not necessarily. Regardless, your fertility will decrease in time because chemotherapy harms germinative cells very much. Chemotherapy has a negative impact on all cell types that reproduce quickly (germinative, embryonal, bone marroy, hair follicles, intestinal mucosa etc.). Vomiting is the most common side effect from chemotherapy. Hair loss, sterility, diarrhea, infections, bleeding, anemia etc. occur later.