便秘是一种常见的疾病，但有关其定义和发病机制的认识尚不统一。由于肠道传输时间并不是一个常数，不同时间测的数值有很大差异，不应作为便秘诊断的参数，其时间延长经常因出口梗阻型便秘所致，而非便秘的初始原因。由于便秘病人需要通过增加腹内压和盆腔内压力，产生排便的刺激，导致道格拉斯窝加深、肠疝、直肠内套叠、膀胱膨出、子宫及阴道脱垂及会阴过度下降等功能性改变，继而出现解剖学改变。直肠内脱垂分为两种类型：直肠长度和结构正常的直肠脱垂；以及伴有直肠肌层延长等结构改变的直肠脱垂，通过经肛吻合器直肠切除术（STARR）切除直肠脱垂及直肠膨出，可以明显改善这些功能性和解剖性变化。

Solitary rectal prolapse and concomitant genital prolapse: Classification and new surgical therapy        Antonio Longo. Department of Coloproctology and Pelvic Diseases, Via Maqueda. 8, 90134 Palermo, Italy
Abstract    Constipation is a pathology in which there are many confusing definitions. The ITT (Intestinal Transit Time) is not an absolute and constant value, highly variable, even in the same person. It is often a consequence of obstructed defecation syndrome (ODS) and not a primary cause of constipation. Patients with pelvic dyssynergia (PD) increase the abdominal strain, in an attempt to increase the endopelvic pressure to create the defecation stimulus. It would lead to dynamic to anatomical alterations as following: perineum hyperdescending, the Douglas pouch deepening or an enterocele occurrence, the rectum and bladder dilating towards the vagina, uterine and vaginal prolapse, etc. With the stapled transanal rectal resection (STARR) technique, pre and postoperative dynamic defecography show the regression of such alterations.