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Cancer of the colon or rectum is one of the most common cancers in many countries. Most people who get the disease are over 60, but some are younger. The chance of getting rid of the cancer is greater the sooner it is discovered.

The cancer form is usually called colon cancer or rectal cancer depending on where in the gut cancer begins. The treatment differs slightly. Colon cancer is cancer in the lower 15 centimeters of the bowel.

Symptoms of the colon and rectal cancer

These are some common symptoms that can be due to cancer of the colon or rectum. You can have one or more of them:

  • You have blood in your stool. Sometimes you can see it for yourself. It is more common than it is detected if you are investigated for anemia.
  • You can poop more or less often than before.
  • The stools may have a different shape or appearance than before.
  • You get mucus in the stool.
  • You get hard to poop and it feels like you can’t completely empty the gut.
  • It is unusual, but some may get stomach upset or lose appetite.

Most often, the symptoms of colon cancer and rectal cancer are due to something other than cancer, such as a benign tumor or inflammation of the gut.

Visible blood in the stool may be due to hemorrhoids. Changed bowel habits may be because you have started eating other foods or because the large intestine is irritated, such as for sensitive bowel – IBS.

Still, be sure to be examined for any of these symptoms.

Sometimes a cancerous tumor can cause a bowel obstruction, known as bowel swelling. Then it hurts a lot and the stomach, often at intervals. The stomach can become stretched and it is common to vomit.

Sometimes you get no symptoms

Sometimes the cancerous tumor does not give any clear symptoms and it takes longer before it is detected. Then it may be the metastases that cause the first symptoms, for example, that you feel tired or that you accidentally lose weight. Metastases are the same as daughter tumors.

When and where should I seek care?

Contact a  health care center if you have symptoms that you believe may be due to cancer of the colon or rectum. You can contact many receptions by logging in.


The doctor usually starts with a body examination and feels, among other things, on the stomach, the lymph nodes in the groin, armpits, and neck, and in the rectum. Most are allowed to have blood and a  stool sample. The stool is examined to see if it contains blood.

The intestine is examined

The doctor needs to look into the gut if there can be a tumor.

The examination is often done with a colonoscopy. It is a flexible instrument that is just over an inch thick. The instrument is inserted through the rectum. You will receive painkillers if needed.

There are other, similar instruments that may also need to be used. It depends on how far up the gut you need to be examined.

With the aid of the instrument, the doctor can also take tissue samples and remove small polyps directly. Polyps are outgrowths of the intestinal mucosa. They need to be removed even if they are benign. They can develop into cancer over time.

Larger polyps may need special preparation. Read more in the chapter on Treatment. 

Sometimes the colon can be examined with computed tomography instead of, for example, a colonoscopy. It is called computer colonography or CT colon. Then the doctor will take tissue samples or treat polyps at another time if needed.

If the doctor finds a suspected tumor or polyps

Tissue samples and polyps that are removed are sent on microscopic examination.

Investigations if you have cancer

You need to be examined more if you have cancer. It is to see how and where cancer grows and to be able to plan your treatment.

You will be examined in the abdomen and chest with computed tomography. Your pelvis is examined with a magnetic camera. Some are also being investigated with a PET camera.

The investigation is conducted according to a standardized course of care

You are usually examined according to a  standardized course of care if your doctor suspects you have colon or rectal cancer.

Standardized care processes are a way of organizing the investigation so that it goes as quickly as possible. Among other things, there are times set for the surveys you may need to do. It is often quick to get calls for examinations in a standardized course of care.

Be clear about how the staff most safely reach you so you don’t miss any time.

Treatment for colon cancer and rectal cancer may vary

The most common thing is to be operated on to get rid of the disease. Sometimes you may also need treatment for colon cancer and rectal cancer with cytostatics and radiation therapy.

The greater the possibility of getting rid of the disease the earlier the cancer is discovered. Sometimes spread cancer can also be treated to get rid of it.

A group of different colon cancer and rectal cancer specialists advise on all people who have received any of the diagnoses. Your doctor will contact the specialists so that they can suggest the treatment that they believe will be best for you based on the examinations that have been done. Your doctor will tell you what the specialists will come up with.

You may need surgery immediately if the cancerous tumor has caused a sudden stop in the bowel or caused the bowel to break.


Benign polyps and small cancer tumors that are detected early can sometimes be removed by colonoscopy or other similar instruments that is inserted through the rectum. The polyp is cut or burned and removed for examination under a microscope.

The treatment is sufficient if the doctor sees that the cancer cells are just superficial on the polyp.

The most common procedure is to use a perforation technique or an abdominal incision. Sometimes the surgery can start with peephole technique but need to continue through an incision.

The cancer tumor is removed. In addition, the doctor removes the healthy part of the intestine closest to the cancer tumor and blood vessels and lymph vessels closest to the cancer tumor. It is to reduce the risk of cancer spreading. Then the gut ends are sewn together if possible.

The entire colon is removed if there are multiple cancer tumors or if there is a risk of multiple cancer tumors.

You are anesthetized before surgery. You usually get back anesthesia too. It is part of the pain relief after surgery.

Sometimes a temporary or permanent ostomy is needed

After an operation for rectal cancer, a temporary stoma usually needs to be done, although the bowel ends can be stitched together after surgery. It is to facilitate healing. The stoma is made in connection with the operation.

But permanent ostomy is also common in colorectal cancer. About half of all people who have surgery for rectal cancer get a permanent stoma.

You may also need a stoma that is usually temporary if you have been urgently operated on.

Preparations for the operation

It is good to be in the best possible condition. Be as physically active as you can before surgery.

Stop smoking before surgery , if you usually smoke. The wounds heal faster, you recover faster and you reduce the risk of various complications.

It is also good if you avoid drinking alcohol before and after surgery, to reduce the risk of complications.

You may need to take a break if you are taking medicines for any other illness. Talk to the doctor.

Before the surgery, you get to see an anesthetist to talk about how you will be anesthetized and what pain relief you may need afterward.

After the surgery

You get the pain relief you need after the surgery. Usually, you will also get help from a physiotherapist or physiotherapist to get started and move as soon as possible.

You are usually allowed to eat regular food and drink immediately after surgery or the day after surgery.

You get a catheter in the bladder when you are operated on. The catheter is removed the following day. You who have back anesthesia usually need to keep the catheter as long as you have the anesthesia.

Most people need to stay in the hospital for about a week, a little shorter if you have had colon cancer and a little longer if you have had colon cancer.

It is common to be able to go home one to two days earlier if you have operated with peephole technology.

You may need to stay a day longer if you have had a stoma that you need to learn to care for.

You may also need to stay longer if there has been a complication, for example if you have an infection.

Risk of infections

All operations involve a certain risk of infection. Sometimes an infection is because it leaks where the intestinal ends have been sewn together. Then you may need to be re-operated or a thin tube will be inserted to empty each.

Treatment for colon cancer with cytostatics

Cytostatics is a collective name for drugs that in various ways inhibit cells.

It is common to get cytostatics after surgery. It is to remove cancer cells that may be left and to reduce the risk of cancer coming back and spreading.

For rectal cancer, you sometimes get cytostatic prior to surgery. Then the treatment is combined with radiation.

Cytostatics you get in cures. After a cure, it is usually two weeks’ pause before the next cure begins. The entire period of cures and breaks is three to six months. You do not need to be hospitalized, but you may need to be on sick leave.

The most common thing is getting cytostatic drugs as a drop in the blood. There are also cytostatics in tablet form.

Usually, two different cytostatic drugs are combined. It can make treatment more effective.  

The treatment with cytostatic drugs can make you feel sick, get mucous membranes, feel tired, lose your hair, and the nerves in your hands and feet are affected. Side effects can often be alleviated, read more in the text Cytostatic treatment.

Radiation therapy for rectal cancer

It is common to receive radiotherapy prior to surgery if you have rectal cancer. It is to reduce the risk of relapse or to shrink the tumor to make it easier to remove.

Sometimes the radiation therapy is combined with cytostatic drugs. Cytostatics make cancer cells more sensitive to radiation.

The treatment is given daily for a week or five weeks.

In some people, the cancer tumor disappears after the combined treatment with radiation and cytostatic drugs. Then it may be enough that you come on regular checks instead of being operated on. You will receive treatment if the cancer tumor returns. After ten years, the risk is small. The checks will then cease.

Radiation is avoided if there is little risk that you may become ill again. This is because the treatment can cause problems in the intestine and genitals, among other things. Read more in the chapter How is life affected by a colon or rectal cancer?

Radiation treatment will make you sterile if you are of childbearing age. Therefore, you should be offered to save eggs or sperm before treatment begins. You can read more in the text Fertility after cancer treatment.

Check after treatment

After the operation, you will be given checks, usually after one year and three years. It may vary for different people.

Contact your doctor if you notice any symptoms between the checks. For example, you may accidentally lose weight, have stomach upset or bleed from the intestine.

Pregnancy, fertility, and breastfeeding

Avoid pregnancy if you are being treated for cancer, regardless of your gender. Some treatments can be harmful to a fetus.

Talk to your doctor before starting treatment if you want to try to get pregnant or use your sperm in pregnancy when you are finished.

Read more in the text Fertility after cancer treatment.

Talk to your doctor if you want to breastfeed.

How is life affected by colon cancer and rectal cancer?

Cancer and the treatment of the disease will affect your life in some way. How big the changes will be for you depends on what treatment you need, if you have other illnesses and how you feel otherwise.

You may need rehabilitation. It can be anything from medical help to support you to feel good mentally and socially. It is good if you, together with the healthcare staff, think about your needs as early as possible and how your needs can change over time.

What you feel and how you feel can also vary.

Here are examples of things you may experience after the colon or rectal cancer treatment.

Discomfort with the stomach and bladder

Following a colon or rectal cancer surgery, it may take a few weeks for the bowel to function properly. It can take up to several years if the joint is far down in the rectum.

You may have diarrhea and a lot of gases in the gut if you have received radiation therapy. You may have urinary incontinence or bowel incontinence. Read more about the problems and what help there is in the text Radiation treatment.

Usually to feel tired

It is common to feel very tired. Fatigue can have different causes. Tell the healthcare staff so you can get help. Make sure that your relatives also know so that they understand and can support it.

Physical activity that suits you can make you feel less tired.

Several short rest breaks are usually better than a single, longer rest break.

Vaginal disorders can be relieved and prevented

The radiation treatment can make the mucous membranes dry and fragile. It can bleed, itch or hurt.

The slit opening can become narrow because it has formed scar tissue after the treatment.

You can get help to relieve and prevent trouble. Read more in the text Radiation treatment.

The vagina may change the angle if you have had surgery in the rectum. It can cause trouble with removals so you need to use, for example, bindings. It can also affect how you can have enveloping sex. You or you and your partner can get advice on how you can do instead.

Trouble if you have a penis

It can be more difficult to get a hold and to keep it if you have received radiation treatment or have been operated on for rectal cancer. There are medicines and aids. Here you can read more about having difficulty getting up and running.

An operation can mean that you continue to have ejaculation that goes back into the body instead of out through the penis. It is sometimes called dry ejaculation. Dry ejaculation is harmless but may feel different.

Lust can be affected for several reasons

The desire to have sex can be affected by several reasons, such as how you experience yourself and your situation. There are things you can do for yourself or with your potential partner if you find reduced desire is a problem. You can also get help if you need to. Read more in the text Cancer and sexuality.

Sick leave if you work

Many continue to work. Others may need to be on sick leave for a longer period. The employer is obliged to make it easier for you to come back. Here you can read more about sick leave.

Can I get sick again?

Most people do not get sick again after treatment, but sometimes cancer comes back. It is called relapse or recurrence and usually occurs within two to three years. Then single cancer cells have remained and started to grow again.

The cancerous tumor may recur in the remaining part of the intestine. It is more common for cancer to return in the form of metastases in the liver, lungs or peritoneum.

The treatment varies greatly between people who get the disease back. It depends on various things, for example where cancer has spread.

Sometimes the metastases can be removed. Often, the treatment is combined with cytostatic drugs and sometimes antibodies or radiation. Antibodies are a form of targeted drugs. They prevent cancer cells from dividing and growing. Antibodies you get as a drop in the blood.

Peritoneal metastases can sometimes be treated with a combination of surgery and cytostatics. First, all visible cancer is removed. Then the doctor rinses the peritoneum with heated cytostatic drugs. It is a demanding treatment that takes a long time.

Palliative care

It is common for cancer to not get rid of it if it comes back. Then you will instead receive treatment that can cure cancer and relieve symptoms. It is called palliative care and can extend life for a few years.

Be involved and influence your care

You have the right to be involved in your care whenever possible. The healthcare staff should tell you what treatment options are available. They should make sure you understand what the different options mean, what side effects are available and where you can get treatment.

That way you can help decide which treatment is right for you.

You decide on the care plan

You can make a care plan together with the contact nurse, the doctor and other staff. The care plan should answer questions that are important to you, such as how to get the rehabilitation you need. Here you can read more about the contact nurse and the care plan.

New medical assessment

You can get a  new medical assessment if you are unsure if you are receiving the care and treatment that is best for you. You will then see another doctor, usually at another specialist clinic.

Ask your doctor if you want to know more about how to get a new medical assessment.

Getting a cancer message

There are many ways to respond to a cancer message. You may need plenty of time to talk to your doctor and other healthcare professionals about what the message means. If possible, please let a relative accompany you. The related person can act as a support and help to remember what has been said.

You have the right to understand

You can also ask to have the information written down so you can read it peacefully. Ask questions if you don’t understand. You have the right to receive information in your own language. You also have the right to receive interpreting assistance if you have a hearing impairment.

In many hospitals, there are special nurses called contact nurses who can provide support and help with various practical things. You can also talk to the hospital’s curator.

For many, it usually feels easier once treatment has begun and they know what is going to happen.

You can get support in several places

You can contact Cancer Counseling, the Cancer Foundation or, for example, a patient association. The Gastrointestinal Association is a patient association for people with, for example, colon cancer or rectal cancer, and for relatives.

Here you will find contact information and read more about how you can get advice and support in cancer.

Children also need to know

A minor child has the right to receive information and support based on his or her own needs if a relative is ill. It is the responsibility of care. If you want to tell the child yourself, you can get help with what you have to say. 

Support if you are related

It can feel difficult to be close to someone who is sick. It is common to want to support while you yourself have a strong concern and feel bad.

The Cancer-Related page provides tips on how to handle the situation and what help you can get.

What are the colon and rectal cancers?

The large intestine and rectum are parts of the five to the seven-meter long gastrointestinal tract that takes care of what we eat.

The inside of the large intestine and rectum is covered by a mucous membrane. This is where cancer begins.

It is common for benign growths to form in the mucous membrane called polyps. Sometimes they can develop into cancer. It takes many years.

When the cancerous tumor grows it can cause wounds and constrictions.

The cancer tumor sometimes only grows at the site where it first developed, but it can also spread through lymph vessels or blood vessels to other parts of the body, such as the liver or lungs or to other organs. It’s called metastases or daughter tumors. Here you can read more about how cancer occurs.

Anal cancer – an unusual form of cancer

Anal cancer or rectal cancer is another type of cancer other than rectal and colon cancer. The cancer tumor occurs in other types of cells, close to the ring muscles. The symptoms may be reminiscent of rectal cancer. Sometimes the cancerous tumor can feel like a hardening of the rectum. It can also hurt, for example when you poop.

Radiation therapy and cytostatics are usually enough to get rid of the disease. You will be operated on if the cancer tumor does not disappear from the treatment, or if it returns.

Anal cancer is unusual.

What are the causes of colon cancer and rectal cancer?

It is unclear what colon and rectal cancers are due to, but there are risk factors.

The risk of colon or rectal cancer is higher if you have chronic inflammation of the colon, such as ulcerative colitis or Crohn’s disease.

The risk of you getting sick is higher if close genetic relatives have had colon or rectal cancer.

There are also unusual hereditary polyp diseases that pose an increased risk of colon or rectal cancer, such as Lynch syndrome and hereditary colon polyps. The diseases cause polyps to form in the large intestine, which after a long time develop into cancer.

The genera that have Lynch syndrome and hereditary colon polyposis are often carefully mapped. The people who carry on the inheritance plant are controlled and receive preventive care.

How can I reduce the risk of colon and rectal cancer?

Colon cancer and rectal cancer depend on many things that interact with each other. It is unclear how this is done. However, it seems possible to reduce the risk of bowel cancer somewhat if you follow these tips:

  • Touch you regularly.
  • Be careful about smoking and alcohol.
  • Eat more fruits and vegetables and less with red meat.

Regular examinations if you belong to a risk group

It is important that you be examined regularly if you have an inherited increased risk of bowel cancer or any chronic bowel disease.

Screening in some places

In some regions, there are screening programs for early detection of colon cancer. You will receive a letter with information on how to proceed if you are covered by an offer of screening.

Muhammad Nadeem

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