A health condition that causes symptoms after surgery to treat rectal cancer is called low anterior resection syndrome (LARS). While the symptoms may improve, in most cases, they last for a long period.
In other words, LARS is a condition that causes multiple symptoms after surgery to remove a part or all of the rectum (low anterior resection or LAR). Usually, the symptoms vary among people who develop it, but most of them experience problems with bowel movements and control. In some cases, people with LARS may also experience problems with urination and sexual function, depression, or anxiety.
Furthermore, anyone who has had a LAR will develop a form of LARS. Mild and moderate forms of LARS usually improve over time. You can notice improvements within the first 6 months after surgery, but it is important to understand that bowel function will never return to what it was before surgery. Unfortunately, there is no way to cure LARS. That’s why the goal of the treatment is to relieve the symptoms, prevent serious complications, and improve your quality of life.
What Are The Symptoms of LARS?
People who develop this condition usually experience the following symptoms. Examples include:
- Tenesmus (a feeling like you need to poop but cannot)
- Bowel incontinence (leaking poop)
- Fecal clustering (small bowel movements that repeat several times per hour)
- Diarrhea
- Leaking gas (also known as gas incontinence)
- Fecal urgency (frequent stools)
- Incomplete evacuation (a feeling like the bowel is not fully emptied)
- Dyschezia (difficulty pooping)
- Constipation
Sometimes, people with LARS may also experience other symptoms, including sexual function issues, urinary problems, and mental disorders (including depression). If any of the previous symptoms occur, immediately contact your healthcare professional.
Causes
Generally, LARS is a common adverse reaction to the removal of a part or all of the rectum. It may still happen even if everything goes well, and there are no other complications. Healthcare professionals believe that a combination of factors triggers LARS. Check some of them below:
- Weak anal sphincter muscles – During surgery, the anus muscles can be damaged. However, they control your bowel movements. Furthermore, other cancer treatments may also cause damage to these muscles. For example, radiation therapy, chemotherapy, and others. Most people with rectal cancer need both radiation therapy and LAR.
- Nerve damage – During cancer treatment, nerves that control anal reflexes can be damaged. As a result, it negatively affects the signals that tell when to poop and when not to.
- Loss of poop storage – Surgeons may remove a part of the rectum (sometimes, all of it) during LAR. Therefore, it leaves the end of the colon to replace the rectum, but it is not designed to hold poop like the rectum. As a result, it leads to multiple bowel movements in a short period and a sudden urge to poop.
- Faster colonic transit time – It means that poop moves faster through the colon after LAR. As a result, the bowels do not have enough time to absorb fluids.
Risk Factors
Healthcare professionals have identified factors that may increase your risk of LARS. Check some examples below:
- Extent of rectal removal – The more rectum is removed during LAR, the more likely you are to develop these adverse reactions.
- Radiation therapy – This is a cancer treatment used to destroy cancerous cells in different parts of the body. It uses powerful energy beams that often come from X-rays or protons, but may also come from other sources. People who need radiation therapy to treat rectal cancer (most of them) are at increased risk of LARS. While this therapy is used to shrink the tumor, it may also cause damage to nearby tissue.
- Anastomotic leak – When a new surgical connection (anastomosis) in the bowel does not heal properly, it may lead to leaks into the abdominal area. As a result, it irritates the tissues, causes an increased risk of infections, and LARS.
- Temporary ileostomy – People who wear a temporary ostomy bag are more likely to develop LARS.
- Younger age – According to some data, LARS occurs more frequently among younger people. Experts do not fully understand the cause.
- Previous bowel dysfunction – The risk of LARS also increases if you have had bowel problems before surgery.
Is There a Way To Prevent LARS?
It is not possible to prevent this condition, but there are some things that may reduce the risk. These include:
- Remove less rectum
- Avoid radiation whenever it is possible
- The construction of the rectal reservoir
Diagnosis
Most of the time, doctors diagnose LARS based on your symptoms. They may also ask you detailed questions or use one of multiple formal questionnaires to evaluate your symptoms. Sometimes, it is difficult to diagnose LARS because the symptoms it causes are similar to those of other health conditions, such as small intestinal bacterial overgrowth (SIBO). Furthermore, there are other conditions that may cause similar symptoms. These include irritable bowel syndrome (IBS), chronic radiation proctitis, and small intestinal and bile acid malabsorption.
Treatment
Healthcare professionals usually prescribe different treatments for people with LARS because they depend on several factors. For instance, the severity and exact cause of the symptoms, age, sex, and preferences. Most of the time, physicians recommend medicines, therapies, and lifestyle changes to manage these symptoms. Check below for some common treatments often recommended by doctors for people with LARS:
Medicines
Doctors often recommend medicines for diarrhea and constipation. These include:
- Antispasmodics
- Antidiarrheals
- Bulking agents (such as psyllium)
- Laxatives
Dietary Changes
Commonly, people with LARS can notice that their symptoms improve or worsen with certain foods or drinks. That’s why doctors usually recommend avoiding some foods. Another important factor is to understand the difference between soluble and insoluble fiber. While the soluble type may be beneficial for LARS, the insoluble form may worsen the symptoms. Check some common trigger foods below:
- Gluten
- Lactose
- Spicy foods
- Cruciferous vegetables (including leafy greens, onions, and broccoli)
- Caffeine (coffee, tea, or even chocolate may stimulate the bowels)
- Artificial sweeteners
Physical Therapy
Healthcare professionals may recommend this therapy to develop better control over your intestines. It usually includes biofeedback therapy and pelvic floor exercises.
Bowel Irrigation
When a person with LARS continues to have problems with unpredictable, uncontrollable, or incomplete bowel movements even after medicines and lifestyle changes, doctors may recommend manually clearing the bowels with water. This procedure is known as transanal irrigation (TAI), and you can use it to clear your intestines at home. Furthermore, TAI is very similar to an enema, but it involves more water and a balloon that holds a large amount of water within the colon. In most cases, people who use TAI do not have bowel movements for the rest of the day.
Sacral Neurostimulation
This is an outpatient surgery that is usually recommended by doctors when the previous options do not help relieve the symptoms of LARS. It is called sacral nerve stimulation (SNS), and it helps with urgency, frequency, and incontinence of stool.
Additional Surgery
In more severe cases, doctors may recommend surgery again. During this procedure, surgeons will create a permanent colostomy (ostomy bag). As a result, the poop will come out automatically into this bag.
Frequently Asked Questions
When should I seek care for LARS?
If you have symptoms that resemble LARS, especially after rectum removal surgery, it is recommended to inform your doctor. These symptoms usually improve over time, but if you cannot endure them, discuss them with your healthcare professional.
How long does LARS last?
Most of the time, the worst symptoms appear right after surgery. Over time, you may notice they gradually improve, but it may take up to 2 years to get rid of them.
What is the best diet for low anterior resection syndrome?
Typically, doctors recommend avoiding foods that lead to soft stools (such as caffeine, alcohol, spicy foods, and fatty foods). However, you should adopt a high-fiber diet that helps make your stools more solid in consistency. It may also help with LARS symptoms, such as urgency, diarrhea, and others.
Can low anterior resection syndrome develop immediately after surgery?
Yes. Most people begin experiencing LARS symptoms soon after bowel function returns following surgery. Symptoms are often most severe during the first few months after the operation and may gradually improve over time as the body adapts.
Does everyone who has a low anterior resection develop severe LARS?
No. Although many people experience some degree of bowel dysfunction after low anterior resection, the severity varies. Some people develop only mild symptoms that improve within months, while others experience moderate or severe LARS that significantly affects their daily activities and quality of life.
Can pelvic floor exercises help with LARS?
Yes. Pelvic floor muscle training, especially when combined with biofeedback therapy, can improve bowel control, reduce fecal incontinence, and help some people better manage urgency and frequent bowel movements. Your healthcare provider or a specialized physical therapist can teach you the proper exercises.
Are there foods that can help improve LARS symptoms?
Many people find that eating small, frequent meals and choosing foods rich in soluble fiber, such as oats, bananas, applesauce, and psyllium, helps make stools firmer and more predictable. Drinking enough fluids is also important, but you should avoid large amounts of liquids during meals if this worsens your symptoms.
Can LARS affect emotional well-being?
Yes. Living with frequent bowel movements, urgency, or incontinence can lead to anxiety, embarrassment, depression, and social isolation. If LARS is affecting your mental health, speak with your healthcare provider. Counseling, support groups, and appropriate treatment for anxiety or depression may improve your overall quality of life.
Will I need lifelong treatment for LARS?
Not necessarily. Many people notice gradual improvement during the first one to two years after surgery and may require less treatment over time. However, individuals who continue to experience symptoms may benefit from ongoing dietary adjustments, medications, pelvic floor therapy, or other treatments.
Can people with LARS live a normal life?
Although LARS can be challenging, many people are able to return to work, travel, exercise, and participate in social activities with proper symptom management. Working closely with your healthcare team to find the most effective combination of diet, medications, bowel training, and other therapies can greatly improve your quality of life and help you maintain your usual daily routine. If you have additional questions, ask your healthcare provider.
