I am not certain if 8 year old is too young to have gall bladder problems but others here may know, it can be severe, ask his doctor if this is possible ,does he get any
pain moving from under his ribs on the
right into his
shoulder and back ?Food can irriate it.... just in case , dont give him food later in the evening, low fat diet is best.. There are other expert/Doctor forums here on MH you may want to ask there also.