Ehrlein H J, Reich H, Schwinger M
J Physiol. 1983 May;338:75-86. doi: 10.1113/jphysiol.1983.sp014661.
Rabbits produce hard and soft faeces in a circadian rhythm. This study was undertaken in order to examine the motor function of the colon in relation to the formation of these two types of faeces. Colonic motility was measured in unanaesthetized rabbits using strain-gauge transducers and simultaneous radiography. Three types of contractions were found in the rabbit proximal colon: haustral activity, segmental activity, and mass peristalsis. Distinctly different motor patterns were observed during the formation of hard and soft faeces. When hard faeces were produced, the motor activity of the proximal colon was enhanced. It consisted of segmental and haustral activity. The segmental contractions separated the digesta into faecal pellets and forced them slowly aborad, whereas the movements of the haustra carried the liquid contents back towards the caecum. When soft faeces were produced haustral and segmental activity was reduced and transfer of the digesta through the proximal colon was accelerated by mass movements. In contrast to the proximal colon, the motility of the distal colon was enhanced during the formation of soft faeces and decreased during the production of hard faeces. The results support the concept that hard faeces are chiefly produced by a separation of liquids and solids and by a retrograde transfer of liquid digesta rather than by an increased absorption of water.
兔子以昼夜节律产生硬粪和软粪。进行这项研究是为了检查结肠的运动功能与这两种粪便形成的关系。使用应变片传感器和同步射线照相术在未麻醉的兔子身上测量结肠运动。在兔子近端结肠中发现了三种类型的收缩：袋状活动、节段性活动和集团蠕动。在硬粪和软粪形成过程中观察到明显不同的运动模式。当产生硬粪时，近端结肠的运动活动增强。它由节段性和袋状活动组成。节段性收缩将消化物分离成粪粒并迫使它们缓慢向远端移动，而袋状运动则将液体内容物带回盲肠。当产生软粪时，袋状和节段性活动减少，消化物通过近端结肠的转运因集团运动而加速。与近端结肠相反，远端结肠的运动在软粪形成过程中增强，在硬粪产生过程中减弱。这些结果支持了这样一种观点，即硬粪主要是通过液体和固体的分离以及液体消化物的逆行转运而产生的，而不是通过水分吸收增加产生的。
