Sigmoidocele (also known as

pouch of Douglas The rectouterine pouch (rectovaginal pouch, pouch of Douglas or cul-de-sac) is the extension of the peritoneum into the space between the posterior wall of the uterus and the rectum in the human female. Structure In women, the rectouterine pouch ...

descent) is a medical condition in which a

hernia A hernia (: hernias or herniae, from Latin, meaning 'rupture') is the abnormal exit of tissue or an organ (anatomy), organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal Devel ...

tion of

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...

containing loops of redundant

sigmoid colon The sigmoid colon (or pelvic colon) is the part of the large intestine that is closest to the rectum and anus. It forms a loop that averages about in length. The loop is typically shaped like a Greek letter sigma (ς) or Latin letter S (thus ''s ...

descends (prolapses) into the

rectouterine pouch The rectouterine pouch (rectovaginal pouch, pouch of Douglas or cul-de-sac) is the extension of the peritoneum into the space between the posterior wall of the uterus and the rectum in the human female. Structure In women, the rectouterine pouch ...

(in females), between the

rectum The rectum (: rectums or recta) is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. Before expulsion through the anus or cloaca, the rectum stores the feces temporarily. The adult ...

and the

vagina In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag ...

. This can obstruct the rectum and cause obstructed defecation syndrome.

Classification

Sigmoidocele may be internal if it is only detectable on defecography, or external if it detectable without imaging and associated with a

rectocele In gynecology, a rectocele ( ) or posterior vaginal wall prolapse results when the rectum bulges ( herniates) into the vagina. Two common causes of this defect are childbirth and hysterectomy. Rectocele also tends to occur with other forms of ...

rectal prolapse A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depen ...

. It is a type of posterior compartment prolapse. Sigmoidocele may be classified according to size relative to the pubococcygeal line.The "pubococcygeal line" (PCL) is a reference line which may be drawn on defecography. It extends from the inferior (lower) border of the

pubic symphysis The pubic symphysis (: symphyses) is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attache ...

to the last coccygeal joint. See Bordeianou ''et al.'' 2018. * Small: less than 3 cm between pubococcygeal line and the most inferior (lowest) point of the hernial sac. * Moderate: 3–6 cm pubococcygeal line and the most inferior point of the sac. * Large: more than 6 cm pubococcygeal line and the most inferior point of the sac. The severity of sigmoidocele can be described with reference to the position of the lowest loop of the sigmoid relative to lines drawn on defecography: * First-degree sigmoidocele: above the pubococcygeal line. * Second-degree sigmoidocele: below the pubococcygeal line but above the ischiococcygeal line.The "ischiococcygeal line" is a reference line which may be drawn on defecography. It extends from the inferior (lower) border of the

ischium The ischium (; : is ...

to the last coccygeal joint. See Bordeianou ''et al.'' 2018. * Third-degree sigmoidocele: below the ischiococcygeal line.

Signs and symptoms

Sigmoidocele may not cause any symptoms. * Obstructed defecation syndrome. It has been suggested that a sigmoidocele does not cause obstruction, but rather is a compensatory mechanism which increases rectal pressure and helps evacuation in the presence of excessive perineal descent. * Incomplete evacuation of rectal contents. * Bulge in posterior (back) wall of vagina.

Causes

The phenomenon is caused by a weak section of fascial supports of the vagina (the uterosacral cardinal ligament complex and rectal vaginal septum), which allows a section of peritoneum containing the sigmoid colon to prolapse out of normal position and descend between the rectum and the vagina. The

mesentery In human anatomy, the mesentery is an Organ (anatomy), organ that attaches the intestines to the posterior abdominal wall, consisting of a double fold of the peritoneum. It helps (among other functions) in storing Adipose tissue, fat and allowi ...

of the sigmoid colon (the structure which attaches the colon to the abdominal wall) is termed the mesosigmoid. This structure is very flexible, which means that the sigmoid colon is very mobile and may change position. During defecation it may be pushed down, eventually causing sigmoidocele. Sigmoidocele may be associated with descending perineum syndrome.

Diagnosis

It is not possible to differentiate between a

and a sigmoidocele on vaginal examination. Defecating proctography will demonstrate a sigmoidocele during straining.

Treatment

Surgery is considered if there is a significant hernia combined with symptoms of obstructed defecation. Laparoscopic ventral mesh rectopexy has been used to correct sigmoidocele. This procedure involves inserting a mesh between the rectum and the vagina. The mesh is suspended from the sacral promontory without tension. This acts to support the recto-vaginal septum and elevate a deep pouch of Douglas. If there is prolapse of the middle compartment, sacrocolpopexy may be carried out to surgically correct all pelvic prolapse problems in the same procedure. Other treatment options are anterior resection, sigmoidopexy with rectocele repair, or sigmoidectomy.

Epidemiology

Sigmoidocele normally occurs in females, and is uncommon. Sigmoidocele is detected about 4-5% of the time when defecography is carried out.

Notes

References

{{Female diseases of the pelvis and genitals Noninflammatory disorders of female genital tract Colorectal surgery Gynaecology