First of all this doesn't mean kidney failure.
Kidney failure has other symptoms like loss of appetite,lethargy
,swelling of body in initial period and later on other symptoms due o accumulation of waste in the body like alteration of thinking etc.
The causes of pain in stomach associated with blood in urine may be due to bladder infection,kidney infection
,kidney stones,bladder Tumors etc.
This requires complete investigation like urinalysis
abdomen or CT abdomen etc.
As far as sugar levels are concerned,your brother in law should make all the efforts to control it meticulously otherwise uncontrolled sugar can play havoc with his body,since it can cause various micro as well as macro vascular complications in future.
You should consult a doctor and get the complete and comprehensive treatment from him.