This is because there are a lot of drugs (e.g. Granisetron,
Ondansetron, and Aprepitant) available which are highly effective at controlling these symptoms. So with proper medication, you shouldn't worry too much about vomiting.
Capecitabine comes in tablet form and is taken orally. It commonly causes diarrhea and mouth sores (55% of those who take the drug). The diarrhea is usually mild (the stools just get softer) and can be controlled by drugs such as loperamide.