小肠是消化道中最长的一段,分十二指肠、空肠和回肠三部分。成人小肠全长5～7m,占消化道全长的75%。由于小肠处于消化道的中段,而且具有管腔长、走行迂回弯转、游离度大的特点,所以小肠疾病的早期诊断非常困难。小肠镜的研制和临床应用为小肠疾病的诊断提供了较好的方法。应用 Small intestine is the longest section of the digestive tract, sub-duodenum, jejunum and ileum in three parts. The full length of adult small intestine 5 ~ 7m, accounting for 75% of the digestive tract full length. As the small intestine in the middle of the digestive tract, but also has a long lumen, detours bent round, free features, so the early diagnosis of small bowel disease is very difficult. The development of small bowel and clinical application for the diagnosis of small bowel disease provides a better method. application