I have a constipation.

A : What are your complaints ?  = (What seems to be the problem?)

B    : I have a constipation     (便秘）.

A    : How long have you got it?

B    : Since 4 days ago.

A    : Do you often suffer it?         suffer   遭受到 

B    : Yes, I always have difficulty to pass stool.       stool  大便    pass stool  排便 

A    : Is there a bleeding?

B    : Yes, I’m often bleeding and it’s very painful.

A    : You should eat a lot of vegetables and fruits to get more fiber.       fiber   纤维 

B    : Is it dangerous, doctor?

A    : Yes, if it’s untreated, operation is the best treatment.       untreated  (没有治愈的） 

         I’ll prescribe medicine for you, please also avoid chilli, durian, and tea.        prescribe   开药方 

B    : Alright, doctor. Thank you.