食管与胃的交界形成食管贲门角（His角），该角可以防止胃食管反流和食管裂孔疝的发生，婴幼儿His角不明显，黏膜皱襞构成的防护瓣也不明显，因而易发生胃食管反流，使婴儿容易发生呕吐或溢乳。
B-bod I-bod O B-bod O O O O O B-bod I-bod I-bod I-bod I-bod O B-bod I-bod I-bod I-bod O O O O O O O O B-dis I-dis I-dis I-dis I-dis O B-dis I-dis I-dis I-dis I-dis O O O O O O O B-bod I-bod I-bod I-bod O O O O B-bod I-bod I-bod I-bod O O O O O O O O O O O O O O O O B-dis I-dis I-dis I-dis I-dis O O B-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym O