Allah says in the Quran:
Allah tasketh not a soul beyond its scope 2:286
He Also says:
Allah would not place a burden on you, but He would purify you and would perfect His grace upon you, that ye may give thanks 4:6
The prophet PBUH said:
Religion is very easy and whoever overburdens himself in his religion will not be able to continue in that way.
Sheikh Sayyed Sabiq wrote in this book Sunnah Creed:
People with unusual circumstances (i.e. women with "prolonged flows of blood"), people who cannot control their urine, people with flatulence, and so on, should perform one ablution for each prayer whether their problem exists all or part of the time or not. Their prayers will be acceptable even while their problems are occurring.
It was reported by Aisha (the wife of the Prophet):
A’ishah said: "Fatimah bint Abi Hubaysh came to the Prophet, peace and blessings be upon him, and said: ‘O Messenger of Allah, I am a woman who experiences Istihadah and I do not become clean from bleeding. Should I forget about Salah?’ He said: ‘No, that is from a vein; it is not menses. When your period starts, then stop praying, and when it ends, wash the blood from your body and pray again.’"
Many scholars say the same applies to a person who suffers from medical condition (constant gas passing for example). You can make the same Sunnah Prayers (like Taraweeh) with the latest Wudu you did for the last Fard. So you make Wudu for Isha, and regardless of what happens you only need to make Wudu before Fajir again (Hanafi + Hanbali). Shafi scholar performing only one Fard prayer is the way to go.
The best solution would be to find a medical solution if possible.