Praise be to Allah.
We put this question to Shaykh Muhammad ibn Saalih al-Uthaymeen, may Allaah preserve him, who answered as follows:
In the Name of Allaah, Most Gracious, Most Merciful. Praise be to Allaah, the Lord of the Worlds. This is not part of the Sunan al-Fitrah, but if there are too many hairs then they should be removed, so that they do not get contaminated with any impurity when using the toilet.
There are reports in the Sunnah of the Prophet (peace and blessings of Allaah be upon him) which indicate that the pubic hairs should be removed, as it was reported that the Prophet (peace and blessings of Allaah be upon him) said: The fitrah consists of five things, one of which is removing the pubic hairs. (Reported by al-Bukhaari).
The Prophet (peace and blessings of Allaah be upon him) also set a time limit of forty days, and the hair should not be left any longer than that,because of the hadeeth of Anas ibn Maalik (may Allaah be pleased with him), who said: He set us a time limit of no more than forty days for trimming the moustache, clipping the nails, plucking the armpit hairs and shaving the pubic hair. (Reported by al-Bukhaari, 10/284 and Muslim, 1/222).
The fuqaha discussed the proper etiquette of removing the pubic hair and said that it is mustahabb to start shaving the pubic hair from beneath the navel, and to start on the right hand side, and one should also be concealed from the sight of others when doing this. One should also bury and hair or nail clippings removed.
The reasons behind removing this dirty hair could also be applied to the hair on the testicles and around the anus, if impurity (najaasah) gets attached to it, because the purpose it to be comepletly clean and pure and keep away from anything that may cause dirt and impurities to cling to the body. In this case, removing this hair is a good thing. With the regard to women, the rulings on removing the pubic hair are the same as the rulings for men. And Allaah knows best.