​​DISCLAIMER: The following information has been gathered from various sources, including Medical Professionals and experts in the field. This is in no way a medical text, but can be used as a helpful set of information that will hopefully give you an understanding and basic knowledge of the subject.
Types of Anorectal Malformation (ARM) Seen in Boys
​​In boys, the pelvis contains several important structures. The diagram below shows a typical male anatomy:
Urinary System:​
Ureters: These tubes carry urine from the kidneys to the bladder.
Bladder: Stores urine.
Urethra: Carries urine from the bladder to the outside of the body. In males the urethra also plays a role in the reproductive system.
Digestive System:
Rectum: The final section of the large intestine, responsible for storing faeces (poo).
Anus: This is a muscle that controls the ability to hold faeces (poo).
Reproductive System:
Composed of the prostate gland, seminal vesicles, vas deferens, and parts of the urethra involved in both urinary and reproductive function.
Pelvic Floor Muscles:
These muscles provide support to the bladder, intestines and reproductive organs.
They play a role in passing urine, faeces (poo) and sexual function.
Ligaments and Nerves:
Ligaments stabilise the pelvis, keeping the organs in place.
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Sensory nerves carry signals to the brain, including sensations like pain, pressure and temperature.
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Motor nerves control muscle movements involved in passing urine, faeces (poo) and sexual activity.
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Anorectal Malformations can occur in different forms and in different degrees of severity.
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ARM in boys can broadly be classified into low and high types.
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.
Children with high malformations tend to have more complex anatomy.
Low ARM:
The anal opening is usually visible to some degree on the skin of the bottom (the perineum).
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It may be closed over by a thin layer of skin, be in a slightly different position or narrower than usual. There may also be a connecting passage to the skin called a fistula.
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High ARM:
The bowel ends blindly at a higher level in the pelvis.
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This type of ARM is seen more often, but not always, in babies with Down syndrome.
Perineal Fistula (also called Rectoperineal Fistula.)
In a perineal fistula the opening for faeces (poo), the anus, is not in its normal position.​
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Instead, the bowel opens onto the perineum, the area of skin between the genitals and the anus.
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This abnormal opening is located outside the ring of muscles (called sphincter muscles) that help control bowel movements.
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The opening may be too small for faeces (poo) to pass.
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If the opening is large enough, soft faeces (poo) may pass, especially in breastfed babies.
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In some babies this type of fistula is found immediately after birth, during the newborn check.
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In others a diagnosis may be delayed until the child begins to show signs like constipation or straining.​
Fistula *​
