It seems that you are experiencing two problems: One, a urethral discharge during defecation that you believe is sperm. Two, a slow second erection after orgasm. Rest assured that the second problem is very subjective. You'll need to measure time during which you need to achieve another erection after the first orgasm. But generally speaking, that time-period is different in different people.

The first problem (sperm coming out during bowel movement) is a serious problem! It is normal that urine is released during a bowel movement because the urethral sphincter also relaxes during a BM; but sperm mustn’t be released. Maybe that urethral discharge was not sperm? You can perform biochemical and microbiological examinations of the urine and sperm in order to diagnose the condition. A microbiological smear from the urethra is also necessary. You can consult a urologist about the condition and receive expert help.