Left inframesocolic space

The left inframesocolic space is a component of the inframesocolic space bounded superiorly by the attachment of the transverse mesocolon, to the left by the mesentery of the descending colon, to the right border by the root of the small bowel mesentery. It is quadrilateral in shape and is larger than the right inframesocolic space.

The space is in free communication with the pelvic peritoneal space on the right of the midline. The sigmoid colon and its associated mesentery form a partial barrier on the left of the midline.

It is important to note that fluid tracking down from the left inframesocolic space can pass freely into the pelvis whereas fluid from the right inframesocolic space passing into the pelvis must pass forwards over the lower ileum.