► 名詞小便  [(4)しょうべん]  [男]    
meaning:  urine  rank: 2☆ 小便がしたい ⇨ I need to pee  
(☛ Not vulgar but used only by men. 尿 (にょう) is used as a medical term)小便  [(4)しょんべん]  [coll]  [peer]  [男]    
meaning:  urine  rank: 3☆ しょんべんしたい ⇨ I gotta pee  
(☛ A colloquial alternative of しょうべん)More examples:- 立ち小便禁止 ⇨ No public urinating