my 19 year old son had PE blood clots six weeks ago. He was hospitalized over night and put on xerelto. There is no history of blood clots on either side of our family and there was no swelling or pain in his legs leading up to this. He is not an athlete, which I have read this can sometimes happen to athletes. He just began having pain in his chest and trouble breathing. After testing, CT scans showed several clots in the lower lobe of his right lung. We had a follow up on July 5th with the Oncologist that saw him in the hospital, and she said his blood levels looked good and his lungs sounded better. We have to wait until October before they can run some tests to try to figure out what might have caused these clots. However, he is now urinating a very dark brown color urine. This has happened twice now. He is a college student and does not live with me but he did send me a photo and it looked as if someone poured coca cola into the toilet. What would cause his urine to be this coca cola color and foamy? Could it be the blood thinners he is taking? Dehydration?