Low Anterior Resection Syndrome (LARS)

Low anterior resection syndrome is a collection of symptoms or issues patients have after undergoing removal of part of or the entire rectum.

Low anterior resection syndrome (sometimes abbreviated LARS) is a common postoperative condition affecting bowel function after a low anterior resection. A low anterior resection is a type of surgery frequently performed to treat rectal cancer.

LARS symptoms can include frequent/urgent stools, clustering of stools, and fecal incontinence.

Learn more about low anterior resection syndrome, including its definition, causes, symptoms, diagnosis, treatment, and potential risks and complications.

What is low anterior resection syndrome (LARS)?

Low anterior resection syndrome encompasses a range of bowel symptoms that can occur following low anterior resection surgery. This surgery involves removing the rectum and part of the sigmoid colon, with the aim of preserving the sphincter muscles and maintaining continence. Despite preserving these muscles, patients often experience significant changes in bowel function, collectively referred to as LARS.

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Causes of low anterior resection syndrome

LARS can occur after a low anterior resection surgery. Removal of the rectum alters the normal structure and function of the bowel. Surgery may damage nerves involved in bowel control, affecting motility and coordination of bowels. The surgical connection of the colon to the remaining rectum (called an anastomosis) may influence bowel function.

Other contributing factors

• Age: Older patients may have more pronounced symptoms due to decreased bowel function.
• Preexisting bowel issues: Patients with preoperative bowel dysfunction may experience more severe LARS.

Symptoms of low anterior resection syndrome

Symptoms of LARS are mainly related to bowel function and may include:

• Frequent bowel movements: Increased frequency of defecation, often more than three times per day.
• Urgency: A sudden, compelling need to defecate, sometimes resulting in incontinence.
• Incontinence: Involuntary leakage of stool, ranging from minor soiling to complete loss of control.
• Fragmentation: Passing small amounts of stool multiple times throughout the day.
• Variable stool consistency: Alternating between loose stools and constipation.
• Tenesmus: A sensation of incomplete evacuation, feeling the need to pass stool despite an empty rectum.
• Difficulty differentiating gas from stool: Loss of ability to distinguish between the need to pass gas and stool.
• Abdominal pain: Cramping or discomfort related to bowel movements.

Diagnosis of low anterior resection syndrome

When diagnosing LARS, a health care provider may use any of these tests to help obtain an accurate diagnosis:

• Symptom assessment: Detailed inquiry about the presence, duration, and severity of symptoms, including bowel frequency, urgency, incontinence, and quality of life impact.
• Physical examination: Examination of the abdomen and rectum to assess for any complications or contributing factors.
• Endoscopic evaluation: Colonoscopy or sigmoidoscopy to visualize the anastomosis site and rule out structural abnormalities or recurrence of cancer.
• Defecography: Imaging study to evaluate bowel function during defecation, identifying issues like rectal prolapse or anismus.
• Anorectal manometry: Measuring pressure and muscle function in the rectum and anus to assess sphincter integrity and coordination.
• MRI or CT scan: Advanced imaging to evaluate pelvic structures and rule out other causes of symptoms.

Treatment of Low Anterior Resection Syndrome

Treatment options range from lifestyle modifications to medication and surgical treatments, depending on the severity of the issue. Treatments may include:

• Dietary modifications: Adjusting fiber intake to regulate stool consistency, avoiding foods that exacerbate symptoms (e.g., caffeine, spicy foods), and maintaining adequate hydration.
• Pelvic floor exercises: Strengthening the pelvic floor muscles through exercises such as Kegels, guided by a physical therapist.
• Bowel training: Establishing regular bowel habits with scheduled bathroom trips to improve control and predictability.
• Antidiarrheal agents: Medications such as loperamide to reduce bowel movement frequency and improve stool consistency.
• Bulking agents: Fiber supplements to help form solid stools.
• Stool softeners: To make bowel movements easier for patients experiencing constipation.
• Sacral nerve stimulation: Electrical stimulation of the sacral nerves to enhance bowel control by improving nerve function and muscle coordination.
• Biofeedback therapy: Techniques to improve muscle coordination and control through visual or auditory feedback during pelvic floor exercises.
• Stoma formation: Creating a temporary or permanent stoma to divert stool into a colostomy bag, often considered for severe cases where other treatments have failed.
• Transanal irrigation: Using a catheter to flush out the rectum and lower colon, reducing stool urgency and frequency.

Psychological support

• Counseling: Psychological support and counseling to help patients cope with the emotional and social impacts of LARS.
• Support groups: Participation in support groups to share experiences and coping strategies with others who have similar conditions.

Follow-up care

• Regular check-ups: Routine follow-up appointments to monitor treatment progress, adjust management plans, and address any complications.
• Continence management programs: Consultation with specialized healthcare providers for ongoing support and management strategies.

Potential risks and complications

Complications of untreated LARS

• Continued bowel dysfunction: Persistent symptoms affecting quality of life, including social isolation and decreased work productivity.
• Emotional distress: Anxiety, depression, and other emotional impacts due to the ongoing challenges of managing LARS.

Treatment risks

• Side effects of medications: Gastrointestinal upset, constipation, or allergic reactions.
• Surgical risks: Infection, bleeding, and complications related to anesthesia for surgical interventions.

Long-term considerations

• Chronic management: Ongoing need for monitoring, dietary management, and pelvic floor exercises to maintain control and prevent recurrence.
• Impact on lifestyle: Adjustments to diet, exercise, and daily routines to manage symptoms and support overall well-being.

Impact on quality of life

• Physical comfort: Reducing symptoms and improving bowel control can enhance physical comfort during daily activities.
• Emotional well-being: Effective management can alleviate anxiety, depression, and the social stigma associated with LARS.
• Independence and confidence: Improved control and confidence to engage in social activities, work, and travel without fear of accidents.

Low anterior resection syndrome (LARS) is a challenging condition that can significantly impact an individual’s physical, emotional, and social well-being. Early diagnosis and appropriate treatment are crucial for improving symptoms and preventing complications. Understanding the causes, symptoms, diagnostic methods, and treatment options is essential for effective management. If you or a loved one are experiencing symptoms of LARS following a low anterior resection, consulting with a health care provider will help develop a comprehensive treatment plan tailored to your specific needs and circumstances.