Option 1: Creatinine is a normal constituent of urine, as it is a waste product of muscle metabolism. It is filtered by the kidneys and excreted in urine.

Option 2: Urea is also a normal constituent of urine, as it is the end product of protein metabolism. It is produced in the liver and excreted by the kidneys.

Option 3: Uric acid is a normal constituent of urine, as it is the end product of purine metabolism. It is produced in the liver and excreted by the kidneys.

Option 4: Ketone bodies are not normally found in urine, as they are produced during abnormal metabolism of fatty acids. Presence of ketone bodies in urine may indicate a metabolic disorder, such as uncontrolled diabetes or starvation.

Therefore, the correct answer is option 4, as ketone bodies are an abnormal constituent of urine.