Rectal biopsy
What is Rectal Biopsy?
A rectal biopsy is a procedure where a small piece of the lining of the inside of the lower bowel is removed, so that it can be examined under a microscope (histology).
Why Might my Child Need a Rectal Biopsy?
A rectal biopsy is recommended when a child’s lower digestive system is not functioning properly due to structural issues, injury, or disease. The most common reason for strip rectal biopsy is:
- Hirschsprung Disease: A condition where a variable length of the lower part of the bowel lacks the nerve cells needed to move stool effectively, leading to a blockage.
Your paediatric surgeon will explain why a rectal biopsy is the best option for your child and discuss what to expect during the procedure.
How Long Does the Operation Take?
The surgery itself takes around 15-20 minutes, but the overall process, including anaesthetic time, and waking up in recovery, will last around an hour.
You will be away from your child for about an hour until they are ready to be seen in the recovery room.
You’ll be notified just as they are waking up so you can be with them as early as possible.
Types of Rectal Biopsy
There are two main types of rectal biopsies performed in children, depending on their age:
- Suction Rectal Biopsy: This is the most common type of biopsy in children. It does not require a general anaesthetic, but can only be performed up to about three months of age.
- Strip Rectal Biopsy: Over three months of age a suction rectal biopsy does not give a reliable result, so a strip rectal biopsy is performed. This requires a general anaesthetic.
What Happens During a Suction Rectal Biopsy?
A suction rectal biopsy can be performed at the cotside with an awake baby. The baby is commonly given sucrose (sugar water), which acts to relieve pain and to calm them.
- A purpose-designed instrument is inserted into the baby’s anus.
- Suction is applied to the biopsy instrument using a syringe. This pulls a small piece of the lining of the lower bowel into the biopsy instrument.
- A small blade then amputates this biopsy.
- Up to three biopsies are usually taken in this way.
Depending on your child’s condition, this procedure takes a few minutes only. Your paediatric surgeon will provide detailed information about the procedure beforehand.
What Happens During a Strip Rectal Biopsy?
A strip rectal biopsy is performed as a day case procedure in an operating room under general anaesthetic.
- Your child is given antibiotics via an intravenous line (a ‘drip’)
- A small piece of the lining of the lower part of the bowel is excised via the anus
- The biopsy site is then sewn closed with absorbable sutures.
- A single biopsy is taken of a strip of rectal mucosa.
Depending on your child’s condition, this procedure takes less than half an hour. Your paediatric surgeon will provide detailed information about the procedure beforehand.
What to Expect After a Rectal Biopsy
Your child will be observed for a short period of time. If they are well they will then be able to leave.
There is usually no pain at the biopsy site, as that part of the bowel does not have pain fibres.
There may be a small amount of blood with the next bowel motion. This is usually blood that has collected from the wound, rather than ongoing active bleeding.
The biopsy will be sent to the laboratory for processing. It may take a few days before your surgeon is able to ring you with a result. In the meantime, your baby can have normal care.
Caring for Your Child at Home
Once your child is discharged, you’ll receive guidance on caring for them at home. In most cases there is no special or different care required after a rectal biopsy.
Your surgeon will provide specific aftercare instructions tailored to your child’s needs.
Possible Complications after a Rectal Biopsy
While a rectal biopsy is generally safe, there are potential complications to be aware of:
- Bleeding: This can occur in approximately 1 in 200 biopsies. It is only a risk with suction rectal biopsies, as the edges are sewn closed with a strip rectal biopsy. Bleeding is generally recognised immediately, and usually stops with pressure.
- Perforation: There have been isolated reports of perforation of the bowel with a biopsy. None of your surgeons have ever seen this occur.
- Insufficient biopsy: The biopsy needs to be deep enough to sample the layer of the bowel where nerve fibres normally sit. If the biopsy is too shallow or too low it may not give a readable result. If that occurs, the biopsy will need to be redone. This is more of a risk with suction rectal biopsies, which is partly why three specimens are taken.
If you notice any concerning symptoms, contact your surgeon or healthcare provider immediately.
Does a Biopsy Mean My Child has Hirschsprung Disease?
Not necessarily.
Suction rectal biopsies are generally performed where we have a high suspicion your child has Hirschsprung Disease.
Strip rectal biopies are performed in older children, typically when they have long-standing constipation. In most of these cases we are performing the test to rule out Hirschsprung Disease, rather than because we expect to find it.
We will tell you beforehand what we expect the chances of Hirschsprung Disease to be. It is rare for Hirschsprung Disease not to be diagnosed in early infancy.
When to Contact Your Surgeon
Seek medical attention if your child experiences any of the following:
- Fever above 38.5°C.
- Obvious pain on passing a bowel motion.
- Ongoing bleeding from the anus.
Frequently Asked Questions (FAQs) About Rectal Biopsy
Are there other ways of diagnosing Hirschsprung Disease?
There are ways of giving us clues, but not as much as a biopsy. A contrast study (x-ray dye test) can suggest Hirschsprung Disease, as can pressure studies of the lower bowel (anorectal manometry). Neither is quite as accurate as a rectal biopsy, which is why your surgeon has recommended rectal biopsy for your child.
My child is constipated, do they have Hirschsprung Disease?
Probably not – constipation is very common, Hirschsprung disease is very rare. Constipation is something which develops, whereas Hirschsprung Disease is present at birth.
Learn More About Hirschsprung disease
For more details, please visit our Hirschsprung Disease page.
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