question: Hi I have a kidney stone and currently under hospital for it however they are just advising me to drink fluids.. I have increased my water intake to 4litres a day and as a result I am visiting the toilet more.  In addition I have noticed that the tip of my penis is getting red blotches on it.  On the days I don't drink as much water I don't seem to get these but when I ensure I drink regularly I get the blotches back.  I am not sexually active at present.  I am 36yo male, 5ft 11 and 207lbs