腹膜腔由于腹膜反折而被分成若干部分,其中横结肠系膜把腹膜腔分成上、下二部分,上部的腹膜后区被肾筋膜分成肾旁(包括前肾旁和后肾旁)间隙和肾周间隙。二者向下延伸,在进入骨盆前融合。位于横结肠、系膜上或腹膜后的脓肿,以及腹腔内的其他非结肠旁脓肿一般不影响结肠,而极大多数位于横结肠系膜下的脓肿可影响结肠。在钡剂灌肠检查中,除了结肠旁肿块外, The peritoneal cavity due to peritoneal fibrosis is divided into several parts, including the transverse mesocolon peritoneal cavity into the upper and lower two parts, the upper part of the retroperitoneal area is divided into renal fascia (including the anterior para-renal and para-renal peritoneal space) and Peritoneal space. Both extend downward and merge before entering the pelvis. Abscesses located on the transverse colon, mesangial or retroperitoneal, and other non-colonic abscesses in the abdominal cavity generally do not affect the colon, whereas the vast majority of abscesses located in the transverse mesocolon affect the colon. In barium enema examination, in addition to the mass next to the colon,