If a person doubts whether or not his penis entered the body...
If a person doubts whether or not his penis entered the body of the woman up to the point of circumcision it is not obligatory for him to take bath. 357. If (God forbid!) a person has sexual intercourse with an animal and semen comes out of his body it is sufficient for him to take bath, and if semen does not come out and he was with ablutions at the time of committing the unnatural act even then taking a bath is sufficient for him.
However, in case he was not with ablutions at that time the obligatory precaution is that he should take bath and should also perform ablutions. And the same orders apply if one commits sodomy with a man or boy. 358. If semen moves from its place but does not come out or the person concerned doubts whether or not semen has come out of his body, taking bath is not obligatory for him. 359.
If a person cannot take bath but can perform tayammum he can have sexual intercourse with his wife even when the time for prayers has commenced. 360. If a person observes semen on his dress - and knows that it is his own semen and he has not taken bath on that account, he should take bath. He should also re-offer those prayers about which he is certain that he offered them after the discharge of semen.
However, it is not necessary for him to re-offer those prayers about which there is a probability that he offered them before the discharge of semen. Unlawful Acts for Ceremonially Unclean Person (Junub) 361. The following five things are unlawful for junub: (i) To touch with any part of his body the writing of the holy Qur'an or the Names of Almighty Allah in whichever language they may have been written.
And it is better that the names of the holy Prophet and Imams and Lady Fatima Zahra (peace be on them) should also not be touched in that condition. (ii) Entering Masjidul Haram or Masjidun Nabi, even though it may be only entering from one gate and going out of another. (iii) To stay in all other Masjids except Masjidul Haram or Masjidun Nabi, and similarly, on the basis of obligatory pre- caution, to stay in the shrines of the holy Imams.
As regards the Masjids other than Masjidul Haram and Masjidun Nabi, however, there is no harm if a person enters through one gate and goes out of another (iv) To go and place something in the Masjid, or to enter or take out something from it even from outside. (v) To recite any one of those verses of the holy Qur'an on the recitation of which performance of prostration becomes obligatory.