Salaah of a sick person

Q: My mother is 83 years old and has dementia. She cannot perform salaah because she cannot remember and is not paak. What will be her situation for the missed salaah?

Q: I can walk easily, can stand for a long time, but the problem is to bend my knees. So I can't make sajdah easily. My doctor advised me not to do salah by normal way? How do I perform my salah?

Q: I cannot sit in qa'dah position in salaah. Normally we use a chair only for qa'dah and sajdah and I stand in qiyaam. A person told me that I cannot stand in while performing salaah in jamaat. The reason being that you will not in be line with the saff and I will be standing in front of the the saff due to the chair being in line with the saff. Should I sit or stand?

Q: I got colostomy bag installed on my stomach due to cancer 2 years ago. As I have no control of my stool, it passes away in the bag without any signs or senses. How can I perform salaah as najaasat is with me almost 24 hours a day. Also, is it compulsory for me to perform sunnah salaah and Nawafil etc.?

Q: If a person has a horrible headache, and the motion from standing to sitting to Sajdah etc aggravates it, can one sit for Salaah?

Also if a person has had a very hectic day, and it feels like they are almost about to fall over, is it permissible to sit and read Salaah? 

Q: While lying in bed I am sometimes unable to face the Qibla as I need assistance and it is difficult for my wife to do it alone. Should I still raise my head or can I read salaah lying flat down (by raising my head I will not be face to Qibla still)?

Q: If a person is unable to do sajdah on the floor due to health problems, does one need to do sajdah on a table if sitting on chair and reading salah or is it permissible to bend down in sajdah whilst in the sitting position on a chair?

Q: Can we offer the first rakah of namaz by standing and other rakaats by sitting?

Q: I often do work in hospitals and come across Muslim patients. When speaking to them, I realise that they are not reading their salaah because sometimes they have urine catherters attached to them/nappys/weak in bed and unable to keep themselves paak. Some say they just don’t feel clean in hospital environment or are too weak to make wudhu, etc. How must I advise them?

Q: When a person feels dizzy, how should he perform namaz? It is very difficult to go into ruku or sajdah. What will be the right way of performing ruku and sajda?