Stain of faeces inside clothes

Dear brother today i took ghusal and did proper istinja when i wore clothes and i have piles i scrath my backside. Later i check my clothes i saw stain which i dont know whether it was the blood from lump or it was feaces. Say for example if it was feaces. Does places where i sat became najis. Even my trouser inside i see stain but outside i dont. Does places became najis.

The other day i woke up and saw my clothes were wet due to urine. I change my clothes and when i went back to room i check my bedsheet and blanket is dry should i wash them.

Also if your cloth have dry urine and then you have a wet dream and semen transfer to your bedsheet does bedsheet became najis with urine. because my underware had dry urine.