Sickness

My son started with a urinary tract infection on 4/6/08 since he has had blood work been cathed twice and had a kidney ultrasound all looks good now, problem is he has been through 5 antibiotics and still running slight fever with activity, and is very exhausted also has jelly like yellow/brownish discharge at times and at times appears to be experiencing stabs of pain in his stomach. Doctors are puzzled with all tset coming back negative and so am I has anyone had a similar experience?