What is Colorectal Cancer?

Colorectal cancer refers to a malignant (vs benign) growth of the colon and/or rectum, ie. the final part of our digestive tract before the anus. Colorectal cancer starts as a polyp, or small growth, along the inner wall of the colon and rectum. Not all polyps become cancer and since they usually take years to become cancerous, if at all, there is a potential ‘lead time’ to stop the process and prevent cancer by removing the polyp during a colonoscopy.

Prevalence of Colorectal Cancer

Worldwide, there were 1.8 million new cases diagnosed in 2018.
Colorectal cancer is the most common cancer in Singapore, first among men and second among women (a breast cancer). It was also the 2nd and 3rd most common cause of cancer deaths in Singaporean men and women, respectively.

Based on recent figures from the National Registry of Diseases Office (NRDO) of Singapore, the incidence of colorectal cancer in Singapore rises sharply after 50 years of age, with 5103 men and 4221 women diagnosed with colorectal cancer between the period of 2010 and 2014. In the same report, it was also found that more than 3 in 4 colorectal cancer patients diagnosed, regardless of gender, were above the age of 55.

Risk factors

Numerous risk factors are involved in developing colorectal cancer, including modifiable and non-modifiable factors.
Modifiable factors include lifestyle and behavioural factors such as obesity, physical inactivity and smoking, all of which can potentially increase an individual’s risk of developing cancer if not controlled.

Other factors that cannot be modified include genetic or hereditary factors, such as having family members with colorectal polyps and colorectal cancer. As such, one may never be entirely free of risk.

Thus screening should still be performed to be absolutely sure that one does not have polyps or cancer, and should preferably be done when the patient is well and not displaying any symptoms.

Symptoms and signs

In the early stages when the cancer is small, there are often no symptoms.
Sometimes, patients may present with signs such as per rectal bleeding, which could mimic more common benign conditions like haemorrhoids. However, by the time symptoms arise, the cancer is often larger and possibly of an advanced stage, ie. having already spread to other organs. Symptoms may include signs of ongoing blood loss such as being pale, lethargic, or feeling breathless with minimal exertion (eg. even walking on flat ground). Other sinister symptoms include significant loss of weight or appetite, abdominal pain, feeling a lump, or bloating. Patients may also experience a change in bowel habit, such as having alternating diarrhoea and constipation or stools with decreased calibre (narrow or pencil-thin).

As symptoms often present only later or mimic more common benign conditions like piles, the majority of colorectal cancers are still only diagnosed in their advanced stages, having already spread beyond the colon or rectum. But this can be easily avoided if people go for screening, ie. when they feel well.

Laparoscopic surgery

The most common and effective treatment for colorectal cancer is surgery, which removes the affected portion of the colon with the cancerous growth. If cancer is discovered in the early stages, this can produce an excellent outcome. Other treatments include chemotherapy and radiotherapy, but this is usually reserved for more advanced cancers which have spread beyond the colon and rectum.

At Mark Wong Surgery, laparoscopic surgery is the preferred method of surgery and is also recognised as the standard for colorectal cancer surgery in developed countries such as Singapore. Also known as ‘keyhole’ surgery, this technique uses advanced technology (including 3D and high-definition optics) to perform surgery through small cuts on the belly.

Compared with conventional ‘open’ surgery that utilizes bigger cuts, the smaller cuts in laparoscopic surgery mean the wounds are smaller and patients experience less pain. The internal organs are also less exposed to the cold operating room environment, reducing the chance of infection, and allowing patients to resume eating faster after surgery. Put together, all these translate to a shorter hospital stay and faster return to normal activities.

Robotic Surgery

At Mark Wong Surgery, our specialist is also trained in Robotic colorectal surgery, one of the latest advancements in laparoscopic surgery. It makes use of a robotic console from which the surgeon controls a robotic machine that performs the surgery through small cuts in the belly.

Robotic surgery is an even more precise method of keyhole surgery than laparoscopic surgery, as the robot has more degrees of movement in wielding the instruments, similar to that of the human wrist. It is also more stable, providing stereoscopic 3D vision and better magnification, enable more precise surgery and stitching.

Such features make it very useful when operating in narrow confined areas like the pelvis, where organs like the rectum are situated. Studies have shown better results in terms of sexual function and continence after robotic surgery compared to laparoscopic surgery. Robotic surgery is often recommended for cancers involving the lower end of the colon, rectum and anus. It has been shown to be as safe as conventional laparoscopic surgery with the above-added benefits.

Prevention & Screening

Colorectal cancer is preventable; since it starts as polyps and takes years to become cancerous, if at all, we can remove polyps to stop them from becoming cancerous. In its early stages, it is even potentially curable. Unfortunately, we are still diagnosing colorectal cancer at advanced stages due to public ignorance and fear of screening.

Based on the NRDO data mentioned earlier with the incidence of colorectal cancer rises sharply after 50 years of age, and it is recommended that adults should screen for colorectal cancer once they reach 50 years of age. In fact, with more patients diagnosed below the age of 50 years, the USA has recommended that the age of screening be lowered to 45 years old. In general, one should go for screening starting 10 years before the youngest case of colorectal cancer (CRC) in the family or at 50 years old, whichever is earlier. For example, if you have a family member with CRC at age 50 years, you should start screening at 40 years old. This is because all CRC arises from polyps which can take several years to become cancer. As such, screening and detecting polyps which can be removed can potentially prevent one from developing colorectal cancer.

Screening for colorectal cancer can begin with a simple FIT (Faecal immunohistochemistry test) kit that detects occult (or invisible) blood in the stool that cannot be seen with the naked eye. FIT kits are free for all Singaporeans and PRs above the age of 50 years. They can be obtained from polyclinics and pharmacies, and are administered at home. If the results are positive for blood, patients should go for a colonoscopy. However, in the presence of overt or frank visible bleeding above the age of 50 years with no recent colonoscopy done, a FIT is not necessary and colonoscopy should be done instead.

Colonoscopy is regarded as the ‘Gold Standard’ for detecting colorectal cancer. At Mark Wong Surgery, our specialist is trained in this procedure which represents a safe and accurate method for detecting colorectal polyps or cancer. A bowel preparation is taken to cleanse the colon of stools before the procedure. The scope is then performed as a day-case procedure under sedation with minimal discomfort. Furthermore, it allows the doctor to perform a biopsy to remove and/or confirm the nature of the lesion seen during the scope. Using high-definition, fibre-optic technology, a flexible tube inserted into the anus allows the doctor performing the procedure to view the inner wall of the colon and rectum in detail, so that any polyps or cancers can be identified, biopsied or removed.

Another alternative is a CT scan for the colon and rectum (CT colonography), but it does not allow for removal or biopsy of suspicious findings, something that will still require a colonoscopy.

Watch more of Dr Mark Wong’s videos and gain insights at https://www.markwongsurgery.com/media/videos/

What it is?

The last 12 to 15 centimeters of the large intestine or colon is known as the rectum. Located above the anus, the rectum temporarily stores stool. In a normal situation, the rectum is held in place in the pelvis (lower part of the abdomen) by ligaments and muscles, together with other organs like the bladder (stores urine) and the womb (in females). If these ligaments and muscles become weak for some reason, the rectum starts to move downwards and may even protrude out resulting in a prolapse.

In the initial stage of this condition, the rectum stays inside the body most of the time. But as the condition worsens, the ligaments and the muscles weaken further and a large portion of the rectum can slip out from the anus and if not treated, there could be a permanent protrusion.

Different types of rectal prolapse

Depending upon its severity, rectal prolapse is graded into the following three types:

• Internal prolapse: In such cases, the rectum does not slip out through the anus and remains within the pelvis or anus.
• External prolapse: The rectum protrudes out through the anus.

The causes and risk factors

Rectal prolapse occurs due to weak ligaments and muscles that cannot hold the rectum in place. While the exact cause of the weakening of the muscles and ligaments is not known, a large number of factors can contribute to this condition due to the repeated strain on the pelvic floor and supporting structures of the rectum. The following are some of them.

• Age, especially when above 40 years old
• Injury from childbirth
• Women having multiple pregnancies
• Previous pelvic surgery
• Chronic cough (eg. chronic obstructive lung disease)
• Chronic constipation
• Prolonged diarrhea

Other than these, cystic fibrosis, multiple sclerosis, spinal cord injury may also result in rectal prolapse. Women are found to be more prone to this than men.

What are the signs and symptoms?

The signs and symptoms of rectal prolapse may be similar to that of the hemorrhoids, including a painful bowel movement, discharge of mucus or blood and a sensation of a lump protruding out of the anus. But unlike haemorrhoids, one may also experience improper control of stools (incontinence), need to strain at stools with little output (obstructed defecation). If the prolapse is serious, it may also affect other organs like the bladder and womb (in women).

Diagnosis & treatment of rectal prolapse

The diagnosis of rectal prolapse is by examination. However, in cases where the prolapse is not obvious, one may need a colorectal specialist and specialized X-rays to diagnose this condition. Treatment of the condition depends on the severity of the condition when diagnosed.

Lifestyle changes may be needed to ensure regular bowel movements with dietary modifications, laxatives and doing pelvic floor exercises. If this does not improve or the condition is serious, surgery may be required.

A colorectal surgeon usually performs the surgery. Using modern key-hole (laparoscopic or robotic) surgery, the rectum is secured to the surrounding muscles and ligaments together with a mesh to provide strength for support. The surgeon will advise on the most appropriate surgical option depending on the overall age and health of the patient.

Constipation is a symptom, not a disease. It is important to establish the cause of constipation in order to treat it effectively.

It is also important to understand that people have bowel movements at different intervals and a healthy range of bowel movements is from three times a day to once every three days. As long as there is no abdominal bloating and pain and there is no urge, then its possibly not time.

However, if one does not move their bowel for more than a week, it warrants investigation. This is especially so if the patient is over 50, the age at which extra vigilance is recommended for signs of colorectal cancer. 

Who Suffers Most

In general, constipation affects the elderly more than the young. Not only do most of the diseases linked to constipation occur in later life, but the incidence of poor nutrition and inactivity increases in old age due to a wide range of reasons.

Causes and Concerns

In attempting to identify the underlying causes of constipation, our specialist will first exclude possible life-threatening organic conditions such as colorectal cancer. In addition, warning signs of colorectal cancer include the passage of blood or mucus during bowel movements, abdominal pain, abdominal lumps and masses, and loss of weight and appetite.

Other possible causes of constipation include metabolic and hormone-related conditions such as thyroid disorders and high calcium levels associated with chronic kidney disease. Medications can also cause constipation, including pain killers, antidepressants, blood pressure medication, iron supplements, calcium supplements, and aluminium-containing antacids, all of which can cause or worsen constipation.

Once these organic causes have been eliminated, functional causes will be considered. These relate to the disturbance in the ‘mechanics’ of bowel movement, and include reduced gut motility (slow transit of stools), muscle incoordination at the anus and rectum and prolapse of the rectum.

Fibre… Too Much Of A Good Thing Is Bad

It is well known that eating a diet rich in fibre is essential to colon health and proper bowel function. Examples include fruits, vegetables, bran, oats and wholegrain bread.

At Mark Wong Surgery, our specialist has seen numerous sufferers of constipation, which began in his previous role as Director of a Pelvic Floor Service at a large restructured hospital. In his experience, Dr Wong cites a growing local ‘epidemic’ of constipation due to an excessive intake of dietary fibre.

Dietary fibre is either soluble or insoluble. When taken in excess, it can lead to constipation with typically pellet-like stools (caused by insoluble fibre), as well as excessive bloating and flatulence (caused by soluble fibre). Conversely, taking too little can also lead to constipation. The key is every individual must take the right amount of fibre for oneself. There is no universal dietary formula or template for everyone and it has to be individualised

How Do We Treat

When constipation occurs, simple lifestyle changes can often remedy the situation. Sometimes, stepping up your exercise routine, drinking more water or eating more or less fibre-rich foods will do the trick. Probiotics and prebiotics are also helpful to promote good gut health and regular bowel movements.

If these measures fail, medications such as laxatives can be used for short-term relief while dietary misalignments are addressed. However, long-term use of laxatives is not healthy, and our specialist believes that most if not all patients can be weaned off their medications by adjusting their lifestyles, involving a combination of both regular exercise and moderating the intake of all food groups.

For those above the age of 45 years and with risk factors for colorectal cancer, a colonoscopy should also be performed to exclude such life-threatening conditions.

Read about colonoscopy

It is therefore a diagnosis of exclusion, ie. until the more life-threatening conditions like cancer or inflammatory bowel disease are excluded, one should not be diagnosed as simply having IBS.

Common symptoms of IBS include:

• Abdominal cramps usually in the lower tummy or on the left side. The pain can be sharp, stabbing or gripping. The pain eases after a bowel movement or after passing gas.
• An urgent feeling to open the bowels
• Irregular bowel habit which quickly changes from constipation to diarrhea. Stool frequency also increases, although patients may not become dehydrated, as is the case with diarrhoea in gastroenteritis.
• There are also deviations in the motions. The stool changes from small to hard pellets to lose.
• Abdominal bloating
• Excessive flatus

There are also some other less common symptoms such as:

• Backache
• Fatigue
• Headaches accompanied by flushing, sweating and fainting
• Agitation
• Pain when passing stool

It is treated with dietary modifications (by eliminating triggers), medications aimed at reducing symptoms (eg. cramps and bloating), as well as starting a regular exercise regimen to reduce stress.

Patients with IBD have varying symptoms, although the most obvious signs are diarrhoea, weight loss, blood in the stool, abdominal pain, and mouth ulcers. Some people may simply present with fistula in the anus and other parts of the digestive tract (eg. Crohn’s disease).

Causes of IBD

It is difficult to point to a particular cause of IBD in a patient. It is believed to be genetic and environmental. There is often a family history of the disease.

There is, however, a strong link with the diet and lifestyle (eg. smoking) in most patients. IBD is associated with specific bacteria in the gut, which in turn is influenced by one’s diet. Some people develop IBD because of their body’s overreaction to the immune system.

Diagnosis of IBD

IBD often presents with a constellation of symptoms and signs, that are common to other conditions of the digestive tract. Since treatment is often lifelong, an accurate diagnosis must be made prior to commencing the necessary treatment.

Some of the tests conducted include:

Blood tests: Full blood count, C-reactive protein, iron levels, erythrocyte sedimentation rate (ESR), renal panel, and liver panel.

Stool tests: Stool culture, stool calprotectin, Clostridium difficile PCR, and microscopy.

Imaging: Abdominal x-ray, chest x-ray, small bowel enteroclysis, small bowel capsule endoscopy, abdominal/pelvic CT scans, and CT/MRI enterogram.

Endoscopy to get tissues for a biopsy. The processes used include colonoscopy, Oesophagogastroduodenoscopy (OGD), and small bowel enteroscopy.

Treatment Options for IBD

IBD flares from time to time. Patients with IBD require medication to control the disease and bring it into remission. This will help to prevent complications, minimize discomfort and help optimize their quality of life. Some of the treatment options include;

• Use of steroids which can be given intravenously, topically or orally
• Immune suppressants
• Antibiotics
• Special diets
• Surgery for complications (eg. fistula, abscess, blockage)

The treatment will be highly dependent on the severity of the IBD and the response to any given medication.