Praise be to Allah.
In general the term marad al-sayalaan (translated here as gonorrhoea) refers to an infected discharge from the urethra in both men and women. This does not have any impact on one's fasting.
With regard to prayer, the state of purity (tahaarah) in invalidated by everything that comes out of the front or back passages, such as urine, stools, wind, prostatic fluid, blood, pus and other secretions.
See question no. 14321
Based on this, the pus or infected discharge that is emitted in the case of gonorrhoea invalidates wudoo’. But if this discharge is continuous and the sick person cannot control it, then he comes under the same ruling as one who suffers from incontinence and cannot control his urine, which is emitted involuntarily.
The ruling is:
If he knows that this emission comes out at certain times and then stops for long enough for him to purify himself and pray, then he has to wait until it stops, even if that means missing the prayer in congregation, and he should do wudoo’ and pray at the time when the discharge has stopped, so long as there is no fear that the time for prayer may end.
But if the discharge is continual and does not stop, then he has to put a piece of cloth over his private part, or something else that will prevent the impurity from spreading and contaminating his body or clothes, and he should do wudoo’ for each prayer after the time for it begins. Then it will not matter if something is emitted after doing wudoo’, even if that is during the prayer.
He may also offer whatever naafil prayers he wishes with this wudoo’, until the time for the obligatory prayer for which he did wudoo’ is over.
This is the answer if what the questioner means is: is prayer and fasting valid if there is continual emission of this pus?
But if what he means is that this person committed the major sin of zina (because most cases of gonorrhoea occur as the result of illicit relationships), then he should note that whoever repents to Allaah, Allaah will accept his repentance, and the one who repents from sin is like one who has not sinned. No matter what sins a person commits, if he then repents to Allaah and turns to Him, and regrets what he has done, then he will find that Allaah is Oft-Forgiving, Most Merciful. Allaah says (interpretation of the meaning):
“Say: O ‘Ibaadi (My slaves) who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allaah, verily, Allaah forgives all sins. Truly, He is Oft‑Forgiving, Most Merciful”
al-Tirmidhi (3540) narrated that Anas ibn Maalik (may Allaah be pleased with him) said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: “Allaah says: ‘O son of Adam, were your sins to reach the clouds of the sky, then you were to ask me for forgiveness, I would forgive them and I would not mind.’” Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi.
The phrase “the clouds of the sky” is used to give an impression of great height, to indicate a huge amount of sins.
End quote from Tuhfat al-Ahwadhi.
See also question no. 9393.
And Allaah knows best.