LARS syndrome, or Low Anterior Resection Syndrome, is a collection of bowel dysfunction symptoms that can develop after surgery to remove part or all of the rectum. It is a recognized consequence of procedures like low anterior resection (LAR) for rectal cancer, where the anal sphincter is preserved. These symptoms can significantly impact a person’s daily life and overall well-being.
Rectal cancer treatment often involves modifying the rectum, the body’s natural reservoir for stool. When this part of the digestive system is altered, the body requires time to adapt, and bowel function abnormalities can arise. While these surgeries aim to maintain bowel continuity and avoid a permanent colostomy, LARS can lead to challenges that persist for months or even years.
Genetic Roots of LARS Syndrome
LARS syndrome is primarily a consequence of surgical intervention, not a direct inherited genetic disorder. Symptoms arise from changes to the anatomy and nerve function of the bowel following rectal cancer surgery, particularly low anterior resection. This procedure involves removing a portion of the rectum and reconnecting the remaining colon, which can disrupt normal bowel control.
The underlying causes of LARS are multifactorial, encompassing anatomical, neurological, and physiological changes. Removing part of the rectum reduces its capacity to store stool, leading to more frequent bowel movements. Nerves supplying the bowels can also be affected during surgery or by radiotherapy, impairing signals that regulate bowel function.
The severity of LARS can also be influenced by factors such as tumor height, the location of the surgical reconnection (anastomosis), and whether the patient received radiotherapy. These elements contribute to how an individual experiences LARS.
Identifying the Signs of LARS Syndrome
Individuals experiencing LARS syndrome often report a range of gastrointestinal symptoms that vary in presentation and severity. A common sign is increased bowel frequency, with a need to empty the bowels multiple times daily. This can manifest as “clustering,” where several small bowel movements occur within a short period, such as one to two hours.
Another frequent symptom is an urgent need to defecate, often with little warning, which can lead to fecal incontinence or accidental stool leakage. Patients may also experience a sensation of incomplete evacuation, feeling their bowels have not been fully emptied. Altered stool consistency, ranging from loose stools to constipation, is also commonly reported.
Some individuals may find it difficult to differentiate between passing gas and stool, contributing to episodes of soiling. Nocturnal bowel movements, where urges occur during the night, can disrupt sleep. These symptoms can be unpredictable, making daily life challenging and leading to discomfort from increased gas and bloating.
Diagnosing and Managing LARS Syndrome
Diagnosing LARS syndrome begins with a thorough clinical evaluation, where healthcare providers inquire about symptoms and their impact on daily life. After low anterior resection surgery, if bowel symptoms persist for over a month or after a protective stoma is closed, LARS is diagnosed.
A tool used to assess LARS severity is the LARS score, a five-question questionnaire that evaluates bowel function. A score above 30 indicates major LARS, which requires a comprehensive treatment approach.
Management strategies for LARS are non-surgical and tailored to the type, severity, and duration of symptoms. Initial approaches involve dietary modifications, such as avoiding foods that trigger softer stools like caffeine, alcohol, spicy, and fatty foods. Gradually increasing fiber intake can help solidify stools and reduce urgency. Medications like loperamide are used to control diarrhea and urgency by slowing bowel motility.
If initial conservative measures are insufficient, second-line interventions include pelvic floor rehabilitation, involving muscle exercises and biofeedback training. Transanal irrigation, a method of washing the bowels with water through a catheter, can also be effective in controlling bowel movements and preventing incontinence. For persistent or severe symptoms, neuromodulation or, rarely, a permanent colostomy may be considered.
Navigating Life with LARS Syndrome
Living with LARS syndrome involves ongoing self-management and support. While symptoms can lessen over time for some, many individuals experience long-term challenges. Patients report that LARS can affect their return to work, social activities, and intimate relationships, as the need to be near a toilet can limit daily activities.
A multidisciplinary care team, including surgeons, gastroenterologists, dietitians, and physical therapists, is beneficial in developing a personalized management plan. Patient education is an important aspect of long-term care, empowering individuals to understand their condition and implement self-care strategies. Although LARS can significantly impact quality of life, consistent engagement with treatment and adaptive strategies can lead to improved bowel control and overall well-being.