Hi - We Have To Do Creatine Test For My

Hi - we have to do creatine test for my son to check his kidneys as he had 2 test with protein levels in his urine increased. This test is to see if his kidneys are working properly. In the mean time he got stomach flu, (last week) - he is still a bit low …a diarehiaa and nosea - is this condition going to affect his cratine levels test results?