Praise be to Allah.
It is not prescribed for a man to examine the channel of his private part or to look into it in order to make sure that there is no urine there. This is a kind of exaggeration and going to extremes, which is contrary to the easy nature of sharee’ah and is also a kind of waswasah (whisper from the Shaytaan). What is prescribed is to wash the tip of the penis after one has finished urinating.
It is also prescribed to sprinkle some water over the private part so as to ward off the waswasah.
Ibn Maajah (464) narrated that Jaabir (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) did wudoo’ and sprinkled his private part. Classed as saheeh by al-Albaani in Saheeh Ibn Maajah.
It says in al-Mawsoo’ah al-Fiqhiyyah (4/125):
The Hanafis, Shaafa’is and Hanbalis stated that when a person has finished washing his private part with water (istinja’), it is mustahabb for him to sprinkle his private part or his trousers with a little water, so as to prevent waswaas, because when he feels any wetness he will think that it is because of the water that he sprinkled, unless he is certain of the contrary. End quote.
Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said in Majmoo’ al-Fataawa (21/106):
With regard to thoroughly inspecting the penis by squeezing it etc, all of that is an innovation which is neither required nor recommended according to the imams of the Muslims. Similarly, pulling the penis is also an innovation according to the correct view, and that was not prescribed by the Messenger of Allaah (peace and blessings of Allaah be upon him).
Squeezing out urine is also an innovation which was not enjoined by the Messenger of Allaah (peace and blessings of Allaah be upon him). The hadeeth which is narrated concerning that is da’eef (weak) and has no basis. Urine comes out naturally, and when it stops naturally, it is as they say, like an udder: if you leave it alone, it will settle down, but if you pull at it, it will flow.
Every time a person opens his penis, something will come out of it, whereas if he leaves it alone nothing will come out. He may even imagine that something has come out – which is waswaas. If the tip of his penis touches his clothes when they are cold, he may think that something has come out when it has not.
There may be urine at the base of penis and if the penis or private part is squeezed with a rock or finger, etc., some wetness may come out. This is also an innovation. That standing urine does not need to be expelled, according to the consensus of the scholars, whether with a stone, a finger or anything else. Rather every time it comes out, more comes, because it keeps leaking all the time. Cleaning oneself with stones (istijmaar) is sufficient and there is no need to also wash the penis with water. But it is mustahabb for the one who cleans himself with water (istinja’) to sprinkle some water on his private part, then if he feels some wetness he can say that it is from this water. End quote.
If the urine does not reach the outside, then it is not subject to any ruling and does not have any effect on wudoo’ or prayer. As for fasting, it is not affected by the emission of urine and a person does not become naajis thereby.
And Allaah knows best.