Thank you for your question.
I am Dr Saha, I shall try my best to help you.
Blood can come from urethra, prostate , seminal vesicles or testis.
There may be -
Sometimes clotting disorder can be an issue.
Often no cause is found.
Usually it comes from seminal vesicles & stop in 2-3 days & no treatment is required.
However, as there is lot of blood, you should consult an urologist or your doctor for an examination to find out the cause.
Analysis of semen, urine & ultrasonography can be needed.
I hope this information helps.
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