谢谢你的回复,我能想到的改变是有:

星期天开始给宝宝头一次从奶粉换成了鲜奶,是ORGANIC的WHOLE MILK(3.8%, 不是HOMO的3.25%).这会引起尿液的酸碱度变化吗?尿酸在酸性大的液体里溶解度低.我是想问医生的,但他在我说话的时候不停地说话打断我,可能根本没听到我说什么.

他喝水一直很多,这几天也没有改变,也没有拉肚子或呕吐,所以应该不是DEHYDRATION引起的.

最近没有吃深色蔬菜或水果.他每一顿饭/点心我都记录的.

另一个不知是否巧合,宝宝一直是吃蒸蛋的,只有出问题那两天是吃的煎蛋.

宝宝其他都无异常,很皮,从早疯到晚.我想如果这现象常见,我就不用太担心了,所以来问问.GOOGLE到一个案例(http://www.consultantlive.com/urologic-diseases/article/10162/11280?pageNumber=1)
里面提到医生该做的有:
A. Ask the mother to bring in the diaper with the reddish stain. If it has been discarded, ask her to bring in any future diaper with a reddish stain.
B. Ask the mother to bring in a first-morning urine specimen for dipstick and microscopic analysis.
C. Ask the mother to observe the baby for signs of colic.
D. Ask the mother to ask the grandparents whether there is any family history of gout, kidney stones, or metabolic or neurologic problems.

My son's Ped only did B, but without mentioning "first-morning". I wonder if a positive answer to D calls for the ultrasonography.