My butthole itches at night. and i tried to go to the toiled and poop but nothing happens.. what is the problem?

Fairly common: This could be several things, most of which are quite common and not alarming. Pruritus ani is rectal/anal irritation and itching (generally worse at night) that can be caused by moisture, yeast, or other mild infections or inflammatory causes. Treatment is generally aimed at ruling out more serious infections (e.g. parasites) and supportive care--perhaps a trial of anti fungal cream or steroid.

May be Fungus?: Best is to see the area to give a better impression. Most common is atopic dermatitis, or skin fungus. You can try over counter Steroid creams ( Cortaid) and or Lotrimin (clotrimazole). Meanwhile try to keep area Clean and dry. Also watch your diet, certain foods may aggravate the area on their way out. If not resolved in a week , must see a Doctor.