Hi, and thank you for coming to JustAnswer.com with your question.
The vomiting when he eats only certain things can wait for a doctors visit, and the blood, depending on the quantity might be able to wait or might not.
Either way, considering that he is obviously having problems with his dialysis he should go see his doctor right away (ie tomorrow).
If he starts having any symptoms like shortness of breath that would be an indication to go to the ER immediately.
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