What is an endorectal ultrasound scan?

Endorectal ultrasound (ERUS) is a specialised imaging technique used to assess the rectum and surrounding structures. It provides highly detailed images of the rectal wall and nearby tissues, helping to diagnose and evaluate conditions affecting the lower bowel. This test is frequently used for staging rectal cancer, assessing anal fistulas, and investigating causes of faecal incontinence.

Why is endorectal ultrasound performed?

ERUS is commonly used to diagnose and assess:

• Rectal cancer – Determines the depth of tumour invasion and involvement of surrounding tissues

• Anal fistulas and abscesses – Identifies the location and extent of fistulas, helping to guide treatment

• Faecal incontinence – Evaluates damage or weakness in the anal sphincter muscles

• Inflammatory bowel disease (IBD) – Assesses complications such as strictures or fistulas in Crohn’s disease

• Rectal polyps – Helps differentiate between benign and potentially cancerous polyps

• Pelvic floor dysfunction – Assists in identifying causes of obstructed defaecation and rectal prolapse

How to prepare for an endorectal ultrasound

You will receive specific instructions before your appointment. In most cases:

• You may be asked to follow a low-fibre diet for 24 hours before the procedure

• A small enema may be required on the day to ensure a clear view of the rectum

• You should inform your doctor if you take blood-thinning medications, as adjustments may be needed

What happens during the procedure?

• You will be asked to lie on your side with your knees drawn up

• A lubricated ultrasound probe is gently inserted into the rectum

• High-frequency sound waves create detailed images of the rectal wall and surrounding tissues

• If necessary, a biopsy may be taken for further analysis

• The procedure usually takes around 15–30 minutes and is generally well tolerated

Are there any risks?

ERUS is a safe and minimally invasive procedure, but as with any medical test, there are some potential risks:

• Mild discomfort – Some pressure may be felt during the procedure

• Minor bleeding – If a biopsy is taken, slight bleeding may occur

• Infection (rare) – If an abscess is present, there is a small risk of infection

What happens after the scan?

• You can return to normal activities immediately after the procedure

• The consultant will review the images and discuss the findings with you

• If a biopsy was taken, results will be available within a few days

Why choose the Midlands Bowel Clinic?

• State-of-the-art technology – High-resolution imaging for precise diagnosis

• Specialist expertise – Skilled consultants with advanced training in endorectal ultrasound

• Comprehensive care – A multidisciplinary approach for optimal treatment planning

Contact us

If you have symptoms such as rectal bleeding, unexplained pain, or changes in bowel habits, early diagnosis can make a significant difference. For expert evaluation and personalised care, get in touch today.