Incomplete Bowel Emptying

Many people recognise the feeling of going to the toilet, but instead of relief, there is a lingering sensation that something is still there. You may find yourself returning to the bathroom, straining longer than usual or feeling uncomfortable for hours afterwards.

Incomplete bowel emptying is far more common in Singapore than most people realise, yet it is rarely talked about. Some people experience it occasionally, while for others, it becomes a recurring problem that affects daily routines, confidence and quality of life. 

What is incomplete bowel emptying?

Incomplete bowel emptying refers to the persistent sensation that stool remains in the rectum after a bowel movement, even though stool has already passed.

This sensation can occur whether bowel movements are infrequent or regular. In some cases, stools may truly remain in the rectum. In others, the feeling arises because the rectum or pelvic floor muscles are not functioning in a coordinated way. But more importantly, the symptom reflects a problem with bowel emptying mechanics, not just stool frequency.

Is it the same as constipation?

Not exactly. While the two can occur together, they describe different symptoms.

The persistent feeling that something is still left behind after passing stool is known as a sensation of incomplete evacuation. This means you may have opened your bowels, but still feel the need to go again shortly after.

Constipation, on the other hand, refers to difficulty passing stools. This may include infrequent bowel movements, hard stools or the need to strain.

In some cases, individuals with constipation may also experience a sensation of incomplete evacuation. However, it is also possible to have this sensation even when bowel movements occur regularly.

What causes incomplete bowel emptying?

The sensation can result from several overlapping factors. These causes are often grouped into the following categories:

Functional causes

• Chronic constipation – when stool becomes hard or dry, it is more difficult for the rectum to expel completely. This can leave residual stool behind, creating the sensation of incomplete emptying even after significant straining.
• Low fibre or inadequate fluid intake – fibre and water help stools form properly and move smoothly through the colon. Without them, stool may be small, hard or poorly formed, making complete evacuation more difficult.
• Poor bowel habits – ignoring the urge to defecate or spending excessive time straining on the toilet can disrupt normal rectal sensation and muscle coordination, leading to inefficient emptying over time.

Pelvic Floor and muscle coordination issues

• Pelvic floor muscle dysfunction – during a normal bowel movement, pelvic floor muscles should relax. If these muscles tighten instead, stool cannot exit fully, even when the urge is strong. This is a common but under-recognised cause.

Structural or colorectal conditions

• Haemorrhoids or anal fissures – pain, swelling or discomfort in the anal canal can make bowel movements difficult and incomplete, as the body subconsciously resists full evacuation.
• Rectocele or rectal prolapse – structural changes in the rectum can trap stool or alter the normal pathway of evacuation, making complete emptying physically difficult.
• Colorectal polyps or tumours – although less common, growths within the rectum or colon can partially obstruct stool passage. This possibility must be considered, particularly in older patients or those with warning signs.

What are the common symptoms associated with incomplete bowel emptying?

People experience this condition differently, but common symptoms include:

• A lingering urge to pass stool after a bowel movement
• Needing to strain or return to the toilet multiple times
• A feeling of blockage, pressure or fullness in the rectum
• Passing small, fragmented or thin stools
• Bloating or discomfort that improves only temporarily after using the toilet

What if it always feels like nothing is coming out when passing stool?

If it consistently feels like nothing is coming out, that leans more towards tenesmus or a defecatory dysfunction, rather than simple constipation.

It may feel like:

• Repeated urge to go, but minimal or no stool passed
• Prolonged straining without relief
• A constant sensation that something is “stuck”

This can be associated with:

• Rectal irritation or inflammation (e.g. proctitis) 
• Pelvic floor dysfunction (dyssynergia), where the muscles do not coordinate properly during bowel movements
• Functional bowel disorders such as IBS
• Less commonly, structural causes affecting the rectum

Is incomplete bowel emptying serious?

Incomplete bowel emptying is often not dangerous, but leaving it unaddressed can lead to ongoing discomfort and complications over time.

Persistent incomplete emptying may contribute to:

• Worsening constipation
• Chronic straining increases the risk of haemorrhoids and fissures
• Pelvic floor dysfunction is becoming more entrenched
• Faecal impaction in severe cases
• Delayed diagnosis of underlying colorectal conditions

When bowel symptoms become habitual or progressively worsen, timely assessment can prevent these issues and improve long-term bowel health.

Who is at risk of experiencing incomplete bowel emptying

While incomplete bowel emptying can affect anyone, certain groups are more likely to experience ongoing or recurrent symptoms, such as:

• Older adults – age-related changes in bowel motility, muscle tone and nerve function can make complete bowel emptying more challenging.
• People with neurological or metabolic conditions – conditions such as diabetes, Parkinson’s disease or spinal disorders can interfere with the nerve signals that coordinate bowel movements.
• People with long-standing constipation – repeated difficulty passing stool over time can alter rectal sensitivity and muscle coordination, increasing the likelihood of incomplete emptying even when bowel movements occur.
• Those with chronic straining habits – repeated straining over time can disrupt normal bowel mechanics, increasing the sensation of incomplete evacuation even when stool volume is low.
• Individuals with sedentary lifestyles – limited physical activity can slow bowel transit and weaken the natural reflexes involved in effective bowel evacuation.
• Individuals with a history of pelvic or colorectal surgery – surgery in the pelvic region may alter anatomy or muscle function, affecting how the rectum empties.
• Women after childbirth – pregnancy and vaginal delivery can affect pelvic floor strength and coordination, raising the risk of inefficient rectal emptying.

When should you see a colorectal specialist for incomplete bowel emptying?

Medical review is recommended if you experience:

• Symptoms lasting more than two to three weeks
• Rectal bleeding, mucus or unexplained anaemia
• Unintentional weight loss or persistent fatigue
• A noticeable change in bowel habits
• A family history of colorectal cancer
• Symptoms that interfere with daily activities or sleep

It may also be worth seeking review if the sensation continues despite dietary changes or occurs alongside repeated straining and discomfort.

How is Incomplete bowel emptying diagnosed in Singapore?

Diagnosing the condition focuses on identifying why evacuation is inefficient. The testing is tailored to the individual, which may consists a combination of:

Diagnosing incomplete bowel emptying focuses on identifying why evacuation is inefficient, rather than treating symptoms alone.

• Medical history and bowel habit assessment – Dr Aaron Poh will ask detailed questions about stool consistency, frequency, straining, diet and symptom duration to identify functional patterns.
• Physical and rectal examination – this allows assessment of anal tone, pelvic floor coordination and the presence of haemorrhoids, fissures or rectal prolapse.
• Colonoscopy – if age, symptoms or risk factors suggest it, a colonoscopy is used to examine the colon and rectum for structural abnormalities, polyps or tumours.
• Imaging or functional tests – in selected cases, specialised tests may be used to evaluate rectal emptying and pelvic floor muscle function more precisely.

How is incomplete bowel emptying treated in Singapore?

With the right diagnosis, incomplete bowel emptying is often very manageable. Treatment is tailored to the underlying cause and introduced gradually, allowing many patients to improve with simple, non-invasive measures before more advanced options are considered.

Lifestyle and dietary adjustments

• Improving fibre intake – fibre helps stools become bulkier and softer, making them easier for the rectum to evacuate fully and reducing the sensation of stool being left behind.
• Increasing hydration – adequate fluid intake keeps stool soft and prevents it from becoming dry or compacted, which can interfere with complete emptying.
• Healthy toileting habits and posture – responding to natural urges, avoiding prolonged straining and using proper toileting posture can significantly improve rectal emptying efficiency over time.

Medications

• Stool softeners or laxatives – when used appropriately, these help improve stool consistency and reduce the effort required to empty the bowels fully.
• Targeted treatments for specific conditions – medications may be prescribed to address contributing issues such as bowel motility problems or inflammation, depending on the diagnosis.

Pelvic floor therapy

• Biofeedback or physiotherapy – these therapies retrain pelvic floor muscles to relax at the right time, improving coordination and allowing more complete bowel evacuation.

Surgical or procedural treatment

• Structural correction when needed – if conditions such as rectal prolapse, rectocele or significant haemorrhoids are present, procedures may be recommended when conservative treatments are no longer sufficient.

How a Colorectal Specialist can help

A colorectal specialist focuses on identifying the true reason behind incomplete bowel emptying, rather than offering one-size-fits-all solutions. Through careful assessment, they can distinguish between functional, muscular and structural causes, while also ruling out serious conditions early.

If incomplete bowel emptying affects your comfort or daily life, booking an appointment can provide clarity, reassurance and a tailored treatment plan. Do remember that early evaluation often leads to more effective treatment and lasting relief.

Frequently Asked Questions