Treatment and care of people with cancer is usually provided by a team of health professionals, both medical and allied health, called a multidisciplinary team.
Treatment for bowel cancer depends on:
- the stage of the disease
- the location of the cancer
- the severity of symptoms
- your general health and wishes.
Treatment may involve the following:
Polyps and in situ cancers can often be removed during a colonoscopy (one of the diagnostic tests for bowel cancer).  If examination of the removed tissue under a microscope shows that the cancer has not spread through the lining of the bowel, no further treatment is needed, but regular follow-up checks are recommended.
Surgery for stage I, II or III bowel cancer may involve removing the cancer and some nearby healthy tissue, and joining the 2 ends of the bowel together again. This type of surgery is called a colectomy  or resection with anastomosis.  Usually, only part of the bowel is removed – this is called a hemicolectomy, partial colectomy or segmental resection. 
If the 2 ends of the bowel cannot be joined, a stoma will be made. A stoma is an opening to the outside of the body, and a special bag (colostomy bag) is attached to the stoma to allow waste to leave the body. This type of surgery is called a resection with colostomy.32 A colostomy may be temporary or permanent. Often the colostomy can be reversed after the lower colon has healed. 
During surgery, some nearby lymph nodes will also be removed to check whether the cancer has spread. 
If bowel cancer has spread to other parts of the body, surgery might be used to remove these spots if there are only a few of them. 
Along with surgery, some people may receive chemotherapy. Chemotherapy given prior to surgery is called “neoadjuvant treatment” and can be offered to reduce the size of the tumour to allow less invasive surgery. Chemotherapy given after surgery is called “adjuvant treatment” and can be offered to reduce the risk of the cancer returning. Chemotherapy can be given as an intravenous injection and/or oral tablets.
For further information on chemotherapy, see chemotherapy
Along with surgery, some people may receive radiation therapy. This can be offered prior to surgery (neoadjuvant treatment), after surgery (adjuvant treatment) or for the management of advanced disease to target local symptoms (palliative treatment).
For further information on radiation therapy, see radiotherapy
Targeted therapy refers to treatment with medicines that are designed to specifically attack cancer cells without harming normal cells.
One type of medicine targets a protein (vascular endothelial growth factor) that helps tumours form new blood vessels. This type includes the medicines bevacizumab and ramucirumab. 
Another type of medicine targets a protein (epidermal growth factor receptor) that helps cancer cells grow. This type includes the medicines cetuximab and panitumumab. 
Immunotherapy involves treatment with medicines that boost the ability of the immune system to attack cancer cells. Immunotherapy can be used to treat some people with advanced bowel cancer, including cancer that cannot be removed using surgery, cancer that has come back after treatment or cancer that has spread to other parts of the body. 
Medicines used in immunotherapy for bowel cancer include pembrolizumab, nivolumab and ipilimumab. 
For further information on immunotherapy, see immunotherapy
Ablation and embolisation
Other methods that can be used to treat a few small tumours in the liver or lungs are ablation and embolisation. Ablation involves treating tumours with radio waves, microwaves, ethanol or freezing. Embolisation involves injecting a substance into an artery to block blood flow to tumours in the liver. 
After treatment, you might need regular physical examinations or colonoscopies to check whether the cancer has come back (recurred). You may also have regular blood tests for cancer-related markers. 
People who are diagnosed with stage IV bowel cancer (where the cancer has spread to other organs, usually the liver or lungs) can have surgery to remove the primary bowel cancer and the secondary cancers. Surgery is unlikely to cure these advanced cancers, but may help you live longer. 
Chemotherapy, targeted therapy with monoclonal antibodies, immunotherapy, or ablation or embolisation may also be used. 
After treatment, you might need regular physical examinations, imaging scans or colonoscopies to check whether the cancer has come back (recurred). You may also have regular blood tests for cancer-related markers.
Recurrent and secondary cancer
Bowel cancer may recur (come back) after treatment. The cancer can recur in the bowel or somewhere else in the body, and is classified as being local or distant. 
Secondary cancer is when the cancer spreads to another part of the body. Secondary cancers from bowel cancer usually develop in the liver or lungs. 
If the cancer does not respond to treatment, supportive care or palliative care can help manage the symptoms and improve quality of life.