Is it fine to add fish in the daily meals after vp shunt surgery or should it be a strict vegan diet? patient is also on chemo for breast cancer

Whoa: Whoever has told you that a person who has had a ventriculoperitoneal shunt needs to eat a vegan diet was simply lying to you. The decision to become a vegan is a moral choice, not a medical one, and a vegan who does not know EXACTLY what they are doing will ruin his/her health. If a health care provider has urged a chemotherapy patient to "go vegan" as Rx, report it to the licensing board.