Dyssynergic defecation is a disorder that can cause a person to have chronic constipation. It occurs when there is a coordination issue between the muscles that control bowel movements.

There are various muscles that work in sync with each other to allow a person to have a bowel movement. If these muscles do not work alongside each other, a person can experience dyssynergic defecation.

The condition can cause a person to have issues such as hard, infrequent stools. This can cause discomfort or lead to other conditions, such as hemorrhoids.

In this article, we will discuss dyssynergic defecation, including its symptoms, causes, and treatments.

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Dyssynergic defecation is a condition that occurs when there is an issue with the muscles that control bowel movements. It may also be known as:

  • anismus
  • pelvic floor dyssynergia
  • obstructive defecation
  • paradoxical puborectalis contraction
  • pelvic outlet obstruction

Several different muscle groups help control bowel movements. Dyssynergic defecation develops when these muscle groups do not coordinate with each other.

Some of these muscles include the pelvic floor and anorectal muscles.

The pelvic floor muscles are at the base of a person’s pelvis. They allow a person to voluntarily urinate and defecate. The anorectal muscles are the muscles of the rectum and anus. The rectum is the end of a person’s large intestine. The anus is the opening that allows stool to exit the body.

If a person has dyssynergic defecation, their muscles do not relax during a bowel movement. In some cases, these muscles can tense up, making bowel movements more difficult.

Additionally, a person may be unable to relax their anal muscles. This means that stool cannot leave the body. Rectal muscles may also be unable to provide the force required to push stool toward the anus.

The exact cause of dyssynergic defecation is currently unclear. Researchers believe that it may result from several factors, including:

  • pregnancy and childbirth
  • trauma or injury, particularly back injuries
  • poor bathroom habits, such as sitting on the toilet for too long
  • inappropriate learning of defecation as a child
  • nervous system issues in the gut-brain axis
  • reduced rectal sensitivity
  • stool taking a longer time to travel through the bowels
  • anxiety
  • stress
  • history of sexual abuse
  • excessive straining

Research from 2016 found that, in a study of 118 people with dyssynergic defecation:

  • 31% developed the condition during childhood
  • 29% developed it after an occurrence, such as childbirth or an accident
  • 40% had no obvious cause

Dyssynergic defecation can cause a person to have chronic constipation. This can cause a variety of symptoms, such as:

  • fewer than three bowel movements per week
  • lengthy, excessive straining
  • hard or lumpy stools
  • feeling of having incomplete bowel movements
  • a feeling of heaviness above the anus
  • a feeling of a blockage inside the bowels
  • anorectal pain
  • abdominal discomfort
  • bloating
  • heartburn
  • backache

A person who has dyssynergic defecation may find that they have to use their fingers to help bowel movements along. This may involve inserting a finger into their rectum to break up stool to make it easier to pass. This is known as digital maneuvering.

A person may also insert a finger into their vagina to push against the wall of their rectum. This technique, called vaginal splinting, helps push stool toward the anus.

There are many ways for a doctor to diagnose a person with dyssynergic defecation. These methods include:

Diet and bowel movement diaries

A doctor may ask a person to keep a bowel movement diary for 1 or 2 weeks. This diary may include:

  • number of bowel movements per day
  • stool consistency
  • level of straining
  • use of digital maneuvers
  • feelings of incomplete bowel movements
  • presence of pain or bloating

A doctor may also ask a person to keep a food diary. This helps a doctor to learn more about a person’s fluid, fiber, and nutrient intake.

Digital rectal examination (DRE)

A DRE involves a doctor inserting a lubricated finger into a person’s anus. This allows the doctor to assess the structure and function of a person’s rectum. If a person has stool in their rectum during a DRE, a doctor can also check its consistency. The doctor can also assess the person’s awareness of stool in their rectum.

A research review from 2023 notes that DREs can help to diagnose dyssynergic defecation in 97% of cases.

Balloon expulsion test (BET)

A BET involves a doctor inserting a 4-centimeter-long balloon into a person’s anus. This balloon attaches to a tube, which the doctor uses to fill the balloon with 50–60 milliliters (mL) of warm water or air. Once the balloon fills, the person expels the balloon into the toilet. A doctor records the time taken for the person to expel the balloon.

A person who has dyssynergic defecation may take longer than is typical to expel the balloon. They may also be unable to push the balloon out.

Anorectal manometry (ARM)

An ARM involves a doctor inserting a probe into a person’s anus. This probe can measure the pressure exerted when a person squeezes or strains. It also measures how well the anal muscles can relax.

An ARM allows a doctor to test the pressure inside a person’s anorectal area. Additionally, an ARM helps a doctor to test rectal sensation, responsiveness, and anorectal reflexes.


A doctor can use defecography to examine changes in the anorectal and pelvic floor areas during defecation.

When using defecography, a doctor inserts 150 mL of barium paste into a person’s anus. They will then ask the person to push the paste out into the toilet. An imaging machine that can see the barium paste inside the person records this process. A doctor can use the information from this recording to check for structural problems during bowel movements.

Colon transit study

A doctor can use a colon transit study, also known as a sitz marker study, to see how quickly stool moves through a person’s digestive system. During this study, a doctor will ask a person to swallow a capsule containing markers that show up on an X-ray machine.

Once the person has swallowed the capsule and had a bowel movement, the doctor can perform the X-ray. This allows the doctor to see how many markers are still inside the individual. If a person has many markers left in their bowels, it means they have a slow digestive system. This can indicate that a person has dyssynergic defecation.

Treatment options for dyssynergic defecation include:

  • avoiding constipating medications
  • eating up to 25 grams of fiber daily
  • drinking an adequate amount of fluids
  • getting regular exercise
  • avoiding postponing defecation
  • attempting 2 bowel movements per day, around 30 minutes after a meal
  • pushing at 50–70% of maximum effort for no more than 5 minutes
  • avoiding digital maneuvering
  • taking fiber supplements
  • undergoing biofeedback therapy, which trains a person to coordinate their rectal and anal muscles
  • taking laxatives alongside biofeedback therapy
  • getting Botox injections into the anal muscle
  • doing pelvic floor physical therapy

Dyssynergic defecation is a condition that can cause a person to have chronic constipation. It occurs due to a coordination issue between the muscles responsible for bowel movements.

The exact cause of dyssynergic defecation is currently unknown. However, researchers believe it may be the result of factors such as injury or childbirth. A person who has dyssynergic defecation can speak with their doctor about what treatment may work best for them.