In 1455 A.D. a petition was submitted to the Ceremonies Board of Joseon's State Council requesting that a list of people be recognized for their filial piety, among other things. First on the list was a student named Lee Hyo-saeng, who definitely went above and beyond the call of duty for a devoted son. Here is the LINK, and here is his story:
議政府據禮曹呈啓: “京畿竹山縣學生李孝生, 事父母盡孝, 晨夕不廢定省, 有所得必獻。 母死三年不輟悲哀, 父病小便不通, 吮而通之。
to the Ceremonies Board of the State Council (議政府據禮曹呈) reported (啓):
“Lee Hyo-saeng, a student from the village of Juksan in Gyeonggi Province (京畿竹山縣學生李孝生), served (事) [his] parents (父母) with the utmost (盡) filial piety (孝). In the morning (晨) [and] the evening (夕), without fail (不廢), [he] checked on them (定省). [If he] had (有) income (所得), [he] invariably (必) gave (獻) it (之) [to them]. [When his] mother (母) died (死), [for] three years (三年) [he] didn’t (不) stop (輟) grieving (悲哀). [When his] father (父) was sick (病) [and] had no urine flow (小便不通), [he] sucked (吮), and (而) cleared (通) it (之).
“경기(京畿)의 죽산현(竹山縣) 학생(學生) 이효생(李孝生)은 부모(父母)를 섬기는 데 효도를 다하여 아침 저녁으로 혼정 신성(昏定晨省) 을 폐하지 아니하고 음식을 얻으면 반드시 이를 바쳤고, 어미가 죽자 3년 동안 비통하고 애통하기를 그치지 않았으며, 아비가 병들어 소변(小便)이 통하지 않게 되자 이를 빨아서 통하게 하였습니다.
HERE is a link to an interesting MBC Radio broadcast that mentions the above story.