<s>[INST] my son is 18 months old and I noticed tonight that the head of his penis was purple the color was darker towards the base of his penis right around where the head flares out and it was lighter at the tip of the penis I couldn t tell for sure if it was painful for him due to him having a fit whenever he gets his diaper changed I couldn t see any strands of hair that could of gotten tangled around it but he also made it very difficult to look. do you have any ideas and if I should call his doctor in the morning [/INST] Hi...bluish discoloration of the end organs like this is a sign of poor or hampered blood circulation. I suggest you to immediately rush to the nearest emergency room please. Even if it gets relieved by itself, we need to know why this is happening and if possible prevent it in future.Regards - Dr. Sumanth </s>