口语中表达“我要上大号(拉屎)”可以说:1. Wheres the bathroom? I need to go number 2.厕所在哪里啊?我得上个大号了。Number 2 :大号2. Hey man, I need to take a dump.兄弟,我想拉屎。Take a dump :拉屎3. I have to visit the john.我得去茅房了。John: 厕所/茅房4. I need to poop/defecate/shit now.我现在想拉屎。Poop/defecate/shit: 拉屎以上四种表达方式都是明确表达要上大号(拉屎),下面是我们通常见到的“想上厕所”的表达方式:1. I want to go to the bathroom.我想上厕所。2. I want to go to the toilet.3. Mummy, I want to go to the toilet. 妈妈,我想去洗手间。4. Excuse me, nurse. I want to go to the toilet. 对不起护士,我想上卫生间5. So, as babies grow older, they will eventually produce the sentence "mother, I want to go to the toilet." 所以,随着小孩子长大,他们最终将会说出这样的句子:妈妈,我想去厕所。6. Bill:Wait a moment, I want to go to the toilet. 比尔:等一会儿,我去下厕所。参考资料有道词典:http://fanyi.youdao.com/?keyfrom=dict2.top“我要大便”怎样用礼貌的英语表达? 1. Bowel movement 排便 Do you have a regular bowel movement every day? 你每天排便还正常吗? 2.Number 2 大号 Wheres the bathroom? I need to go number 2 厕所在哪里啊?我得上个大号了。 3.Take a dump 拉屎 Hey man, I need to take a dump. 兄弟,我想拉屎。 4.John 厕所/茅房 I have to visit the john. 我得去茅房了。 5. Poop/defecate/shit 拉屎 I need to poop/defecate/shit now. 我现在想拉屎。