Low anterior resection syndrome describes a group of symptoms that can occur following colorectal cancer treatment. These can include incontinence, feelings of urgency, increased stool frequency, and other bowel habit changes.

Low anterior resection syndrome can lead to a decrease in quality of life. Doctors may recommend treatments to ease specific symptoms.

This article reviews the symptoms and causes of low anterior resection syndrome. It also discusses diagnoses, treatments, dietary changes, and more.

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Low anterior resection syndrome describes a collection of related symptoms. In a 2016 study, researchers described them as including:

  • incontinence
  • issues of frequency
  • feeling of urgency
  • incomplete emptying

In more recent years, a healthcare initiative came up with a consensus-based description of symptoms. According to the newer standards, the most important symptoms include:

  • bowel emptying difficulties
  • altered stool consistency
  • incontinence
  • urgency issues
  • increased stool frequency
  • variable or unpredictable bowel function
  • soiling
  • repeated painful stools

In a 2023 study, researchers noted that people who experience low anterior resection syndrome fit into two categories. The first describes those who develop incontinence, fecal urgency, and increased frequency. The second describes individuals who develop a sensation of incomplete evacuation of the bowel, constipation, and issues emptying their bowels.

A person can present with symptoms from either category to different degrees. They may also alternate between different symptoms relating to either category.

A partial or total resection of the rectum may cause low anterior resection syndrome. Several factors may lead to its development in some people.

In a 2016 study, researchers suggested that the underlying cause may include one or more of the following factors:

  • internal anal sphincter dysfunction
  • the disappearance of the rectoanal inhibitory reflex
  • a decrease in anal canal sensation
  • a reduction in rectal reservoir capacity and compliance
  • a disruption in local reflexes between the anus and the neorectum, which is the artificial rectum created during surgery

In a 2023 study, researchers cited the above study and explained what it means. The surgical procedure can decrease the amount of stool a person can store and increase pressure. It can also interrupt much of the neural pathways and communication in the rectal area that allows someone to control when they pass a bowel movement.

Learn about different types of surgery for colorectal cancer.

To diagnose low anterior resection syndrome, a person must display at least one symptom, such as incontinence, increased frequency, soiling, or others.

In addition, their symptoms need to cause the individual to experience at least one of the following effects:

  • preoccupation with bowel function
  • dissatisfaction with bowels
  • toilet dependence

A doctor may also assess the effect the symptoms have on:

  • mental health
  • social and daily activities
  • emotional well-being
  • commitments and responsibilities
  • relationships and intimacy
  • roles in the community, school, or work

A 2023 study noted that subtleties in diagnostic criteria can make the diagnosis of low anterior resection syndrome challenging. They suspect actual incident rates of at least some bowel dysfunction may reach up to 90% of all people who undergo a resection procedure.

Treatment for low anterior resection syndrome aims to alleviate specific symptoms.

According to a 2022 study, doctors do not base current treatments for low anterior resection syndrome on clinical evidence. Instead, they follow guidelines according to experts and previous successful treatments.

Treatments can include:

  • dietary changes
  • constipating agents such as loperamide
  • bulking agents
  • pelvic floor therapy

Researchers suggest that future studies using larger cohorts and better study designs should focus on finding effective treatments for those with low anterior resection syndrome.

Currently, no official dietary guidelines exist for people living with low anterior resection syndrome.

In a 2022 study, researchers noted that dietary information for low anterior resection syndrome lacked clinical evidence for its effectiveness. They also noted that evidence often relied on trial and error methods to find foods that may improve bowel function.

In their study, researchers noted that several factors may influence low anterior resection syndrome recovery. They noted that foods that could improve symptoms within 6 months after surgery included oils, poultry, and livestock such as beef.

However, they noted that a person may need to consume a certain amount of each to experience the effects. They also noted that the consumption of oil before surgery may improve outcomes.

Alcohol consumption before surgery may negatively affect outcomes at 6 months. The negative effects may occur due to changes alcohol can cause to the biodiversity of intestinal flora, which refers to the balance of bacteria in the gut.

They also noted that previous studies showed milk may increase diarrhea. Also, not enough evidence exists to determine the effects of fruits or vegetables on low anterior resection syndrome.

The following sections provide answers to common questions about low anterior resection syndrome.

How long does low anterior resection syndrome last?

Low anterior resection syndrome can last for a long time, with some estimates suggesting up to 18 months following surgery.

What are the complications of a low anterior resection?

The rectal region shares close connections with the bladder and sexual organs. Common complications of low anterior resection can involve issues with sexual health, defecation, and bladder dysfunction.

What is bowel dysfunction after lower anterior resection?

Bowel dysfunction after lower anterior resection is better known as low anterior resection syndrome. It involves a group of related symptoms that affect a person’s ability to pass bowel movements.

How does low anterior resection syndrome affect quality of life?

Researchers indicate that low anterior resection syndrome negatively affects a person’s quality of life in several ways. Some ways it may affect someone’s life include sexual and other forms of intimacy, mental health and emotional well-being, and daily or social activities due to bowel dysfunction.

Low anterior resection syndrome describes a group of related symptoms that may occur following lower anterior resection surgery. The symptoms may vary in both severity and what a person experiences. These symptoms can include incontinence, urgency issues, changes in frequency, and more.

Current treatments focus on stopping the symptoms. Dietary changes may help, but scientific data does not support following any specific diet.