Short answer · Medically reviewed summary · Last updated: 2026-04-07

TL;DR: Cloacal exstrophy is a rare, complex congenital anomaly where the bladder and intestines are exposed on the outside of the abdomen at birth, often accompanied by structural abnormalities of the pelvic floor and genitalia. It represents the most severe form of the exstrophy-epispadias complex and requires early, multi-stage surgical reconstruction to address the affected abdominal, urological, and gastrointestinal systems. What exactly is Cloacal exstrophy? Cloacal exstrophy is a severe birth defect that occurs during early embryonic development.

What is Cloacal exstrophy

Name: What is Cloacal exstrophy
Creator: DiseaseMaps Editorial Team
Published: 2015-09-21UTC01:35:15.0000000

What is Cloacal exstrophy? Plain-language, medically reviewed definition plus the lived reality told by patients.

TL;DR: Cloacal exstrophy is a rare, complex congenital anomaly where the bladder and intestines are exposed on the outside of the abdomen at birth, often accompanied by structural abnormalities of the pelvic floor and genitalia. It represents the most severe form of the exstrophy-epispadias complex and requires early, multi-stage surgical reconstruction to address the affected abdominal, urological, and gastrointestinal systems.

What exactly is Cloacal exstrophy?

Cloacal exstrophy is a severe birth defect that occurs during early embryonic development. In a typical pregnancy, the cloaca—a temporary structure that serves as a common channel for the digestive and urinary tracts—divides into separate openings for the bladder and the bowel. In Cloacal exstrophy, this division fails to occur properly. As a result, the bladder is split in two, and the intestine is exposed between these bladder halves on the lower abdominal wall. This condition is frequently referred to as the OEIS complex, an acronym representing the four primary features: Omphalocele (a protrusion of abdominal organs), Exstrophy of the cloaca, Imperforate anus, and Spinal defects.

Which body systems are affected by Cloacal exstrophy?

Because Cloacal exstrophy involves the early development of the pelvic region, it affects multiple systems simultaneously. The primary impacts include:

Genitourinary system: The bladder is often divided into two separate, exposed plates, and the external genitalia are typically malformed or ambiguous.

Gastrointestinal system: The colon is usually short, and the anus is closed (imperforate), requiring surgical creation of an opening for waste elimination.

Musculoskeletal system: The pelvic bones are often widened or separated, and there is a high incidence of spinal cord abnormalities, such as tethered cord syndrome.

Abdominal wall: The omphalocele allows internal organs to protrude through a defect in the abdominal wall near the umbilical cord.

How common is this condition?

Cloacal exstrophy is extremely rare, with an estimated incidence of approximately 1 in 200,000 to 400,000 live births. It is considered a sporadic condition, meaning it typically occurs randomly without a clear family history. While it can affect any gender, some clinical literature suggests a slightly higher frequency in female infants. Due to the rarity of Cloacal exstrophy, it is essential for families to seek care at specialized pediatric centers with multidisciplinary teams experienced in complex reconstructive surgery.

What causes Cloacal exstrophy?

The exact cause of Cloacal exstrophy remains unknown, though it is understood to be a result of a developmental error occurring between the fourth and sixth weeks of gestation. Unlike many genetic conditions, it is rarely inherited; it is not typically caused by anything the parents did or did not do during pregnancy. Current medical research focuses on the disruption of the mesoderm (a layer of embryonic cells) in the lower abdomen, which prevents the normal closure of the abdominal wall and the separation of the pelvic structures.

Next steps

Consult with a pediatric urologist and a pediatric surgeon specializing in complex congenital anomalies.

Connect with the DiseaseMaps.org community to share experiences with other families navigating this rare diagnosis.

Request a referral to a genetic counselor to discuss the nature of the condition and address any concerns regarding future pregnancies.

Seek support from organizations such as the Association for the Bladder Exstrophy Community (A-BE-C) for specialized resources and peer support.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment; always consult with your healthcare provider regarding your specific medical needs.