Differential diagnosis of free fluid in cul de sac (pouch of Douglas)

Dr Craig Hacking and Dr Prashant Mudgal et al.

The cul-de-sac, also known as the pouch of Douglas or rectouterine pouch, is an extension of the postero-inferior reflection of the peritoneal fold between the uterus (anteriorly) and rectum (posteriorly). It is the most inferior aspect of the peritoneal cavity and therefore the first location where free fluid accumulates.



Evidence of fluid within the cul-de-sac is a common finding, and the underlying cause can be thought of as either physiological or pathological. 


Physiological pelvic intraperitoneal fluid in women may be due to:

  • ruptured follicles
  • retrograde menstruation
  • increase in ovarian permeability due to oestrogen influence
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Article information

rID: 39740
System: Gynaecology
Section: Gamuts
Tag: pm, cases
Synonyms or Alternate Spellings:
  • Fluid in POD

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