In girls the pelvis contains several important structures.

Urinary System: 

Made up of the bladder, urethra, and parts of the ureters.
Bladder: Stores urine 
Urethra: Carries urine from the bladder to the outside of the body. 
Ureters: These tubes carry urine from the kidneys to the bladder

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Digestive System: 

Rectum: The final section of the large intestine, responsible for storing stool (poo)
Anus: This is a muscle that controls the ability to hold stool (poo)

​

Reproductive System: 

The female reproductive system helps in reproduction by producing eggs, supporting pregnancy, and giving birth. 

It has internal and external parts. 
The external parts include the labia, the clitoris and the vagina just inside. 
The internal parts include the cervix, the uterus (womb), and the two fallopian tubes each with the ovaries.

Pelvic Floor Muscles: These provide support to the bladder, intestines and reproductive organs. They play a role in passing urine, stool (poo) and sexual function.

Ligaments and Nerves: Ligaments stabilise the pelvis, keeping the organs in place
Sensory nerves carry signals to the brain, sensations like pain, pressure and temperature.
Motor nerves control muscle movements in passing uring, stool/poo and sexual activity.

Female anatomy (Permission needed for illustrations)

      

Anorectal Malformation can occur in different forms and in different degrees of severity. 

Broadly, they can be classified into low and high ARM
Children with low malformations are often expected to have better outcomes than high malformations (i.e. less problems with soiling) but may have problems with constipation

Low ARM: 
The anal opening is usually visible to some degree on the skin of the bottom. It may well be in a slightly different position (sometimes just inside the outmost part of the vagina) or narrower than usual. There may also be a connecting passage to the skin called a fistula.

High ARM: The bowel has a closed end at a high level and does not connect with the anus, or it may connect with another part of the body, usually the bladder, urethra or vagina, through a fistula. 

High ARM: The bowel may have blind end higher up. This is seen most often (but not always) in babies with Down Syndrome. Alternatively, the bowel may open into another structure such as the vagina higher up. If this happens, the urethra is often higher too. This is a cloaca.

Anal stenosis 
Anal opening is very narrow
It may be too small for stool (poo) to be 
pushed out. 

Sometimes the baby passes a thin “ribbon like” stool.
    

Rectoperineal fistula
Rectum opens onto the perineum
This is the area of between the anus and the genitals.
This condition is more common in females and results in an anal opening that is closer to the external genitalia than normal. 
The passage is often tighter than normal, making passing stool (poo) difficult.

This type of ARM may not be immediately recognized at birth and is diagnosed later when the child experiences chronic constipation or difficulty passing stool.         
   

Rectovestibular fistula
Rectum ends just inside the vaginal opening

Another common type of anorectal malformation (ARM) in females. 

This is normally diagnosed soon after birth when faeces are seen coming out of the area very close to the vagina but there can be a delay in diagnosis. 

This malformation may be associated with other abnormalities of the genital tract     

 

Imperforate anus without fistula
In this type of Anorectal Malformation the rectum does not end at the bottom.
   
The anal opening is missing or is in the wrong place.
   
There is no opening on the skin for stool (poo) 
to come out of the body

This can be seen in children with 
Down Syndrome (not always).      
https://link.springer.com/chapter/10.1007/978-3-319-14989-9_12

 

Rectovaginal fistula
An abnormal connection exists between the bowel and the vagina.

This is a rare type of ARM where
bowel contents leak through the fistula, allowing gas or stool (poo) to pass via the vagina. 
The urethra is in a normal position though. 
   
Need image

 

 

 

 

Cloaca
The rectum, vagina and urinary tract share a single common channel

Cloaca is diagnosed in about one of every 20,000 baby girls
The urethra, vagina and rectum are supposed to separate into three separate tubes and openings.

Girls with cloaca are born with their urethra, vagina and rectum connected in one common channel and opening. 

The channel can either be short or long. 
About 60% of girls with cloaca can have two uteruses (uterus didelphys).
    

 

2025 Reviewed by:
Mr.Jonathan Sutcliffe. 
Consultant Paediatric Surgeon. Leeds Teaching Hospital NHS Trust.
Further information may be found:
https://www.gosh.nhs.uk/conditions-and-treatments/conditions-we-treat/anorectal-anomaly
https://library.sheffieldchildrens.nhs.uk/tag/anorectal/
https://mft.nhs.uk/rmch/services/manchester-centre-for-neonatal-surgery/conditions-
https://www.nationwidechildrens.org/conditions/anorectal-malformations-or-imperforate-anus/types-of-anal-malformations
https://www.nationwidechildrens.org/conditions/cloaca
   

Imperforate anus without  fistula
Rectum does not end at the bottom 

The anal opening is missing or is in the wrong place. 

There is no opening on the skin for stool (poo) to come out of the body

     
https://link.springer.com/chapter/10.1007/978-3-319-14989-9_12