Children's Hospital Colorado

Anal Dilation for Patients with Colorectal Conditions

Where comprehensive care, personalized attention and world-class experience meet to treat patients with complex colorectal disorders.



After your child has colorectal surgery to repair of an anorectal malformation, such as an imperforate anus or cloaca, our care team will teach you how to dilate your child's new anus. Anal dilation is done to prevent the natural healing process from closing the recently operated area. The natural healing process causes an anal stricture or narrowing of the anus.

Before colorectal surgery

Order a set of Hegar dilators. You can search online to buy them or ask your surgeon where to get them.

Two weeks after colorectal surgery

You will have a clinic appointment with your child's surgeon. During this visit, they will teach you how to dilate your child's anus. This is a very important appointment and should be scheduled as soon as you know the date of your child's colorectal surgery.

Once the surgeon has chosen the correct size of dilator needed to begin dilations, they will show you the proper technique. You will dilate the anus twice a day. Insert the dilator for 30 seconds twice in the morning and twice in the evening. Always do this before meals. You may need another person to hold your child while you do the dilations.

Each week, the size of the dilator should be increased to the next size. Your surgeon will tell you what dilator size is right for your child. The dilations may become painful when you increase the size. This can sometimes cause parents not to dilate because they are afraid to hurt their child. You will not harm your child during the dilation process. It is important to do dilations every day so that scar tissue does not form and cause strictures (narrowing) of the anus. Anal strictures are a major setback that can be easily avoided by following the dilation schedule as prescribed.

Rectal dilator size goals for different ages

  • 1 to 4 months: #12
  • 4 to 8 months: #13
  • 8 to 12 months: #14
  • 1 to 3 years: #15
  • 3 to 12 years: #16
  • 12 years and older: #17

Decreasing the frequency of dilations

Once your child has reached the desired dilator size and the dilator passes easily twice daily, you will begin to decrease the frequency of the dilations as follows:

  • Once a day for a month
  • Every other day for a month
  • Every third day for a month
  • Twice a week for a month
  • Once a week for a month
  • Once a month for three months

If you have any questions or concerns, do not hesitate to contact us 720-777-6571.