The bowel is divided into two parts – the small bowel and large bowel, also known as the colon. Cancer that starts in the large bowel is known as colon cancer.
The large bowel is part of the digestive system and, as food passes through the large bowel, water and nutrients are absorbed, leaving waste which is passed through the rectum and out of the body.
The colon is very long and is divided into four separate sections. The ascending colon is connected to the small intestine and runs up the right side of the abdomen . The transverse colon runs under the stomach from right to left. The descending colon runs down the left side of the abdomen to the sigmoid colon, an s-shaped bend, that joins the descending colon and the rectum or back passage.
Colon and rectal cancer are often treated as one type of cancer, called colorectal cancer but treatment will depend on where the cancer is located.
Colon cancer can spread to other parts of the body through our lymphatic system and colon or bowel cancer often spreads to the lymph glands first. It can also spread through the bloodstream and often colon cancer will spread to the liver or lungs.
Symptoms of bowel cancer can often be confused with other common conditions, so it is important to always seek medical advice if you experience any of the following changes:
- Change in bowel habit
- Dark stools due to bleeding in the colon
- A lump you can feel in your abdomen
- Pain in the abdomen
- Unexplained weight loss
- Feeling bloated or constipated
Colon cancer is very common cancer, affecting both men and women. Risk factors include:
- Age – it is more common in older people
- Genetics or family history
- Certain medical conditions can make you more predisposed to developing colon cancer, such as Crohn’s disease or ulcerative colitis
- Lifestyle factors including diet
Most patients have surgery straightaway to treat colon cancer, but this does depend on where your cancer is, the size and whether it’s spread to other parts of the body. For high-risk patients they may require chemo first to shrink the tumour(s).
Prof Jamie Murphy performs the following operations to treat colon cancer:
A right hemicolectomy is a procedure to remove the right-hand portion of the colon, including the caecum, ascending colon and a portion of the transverse colon.
The operation will either be performed as a ‘open’ procedure through a long incision in the abdomen, or more commonly as a laparoscopic or keyhole procedure, where a few smaller incisions are made and Prof Jamie Murphy will use a tiny camera and special operating instruments to remove the portion of the colon. The two healthy ends are then joined together.
A left hemicolectomy removes the left-hand portion of the colon, resecting the mid-transverse colon to the descending/sigmoid junction. Similar to the right hemicolectomy, it can be performed as an open or laparoscopic procedure.
Colon cancer surgery aims to remove the diseased part of the bowel and this procedure removes the sigmoid portion, which lies on the left-hand side of the abdomen. The remaining colon is then joined to the top of the rectum.
Will I need to have a stoma after colon cancer surgery?
A stoma is opening from the bowel through the surface of the abdomen which allows body waste to be collected in a bag stuck to your skin, rather than pass through the digestive system. A colostomy or ileostomy are procedures to create a stoma from either the large or small bowel.
You may require a temporary colostomy or ileostomy to give you colon time to heal after surgery – this can then be reversed in another operation. If a large portion of the colon needs to be removed and the remaining ends of the colon can’t be joined, then you may need a permanent stoma, but this will be avoided if possible.
What are the risks of colon cancer surgery?
Although a laparoscopic procedure is less invasive than open surgery, this is still a major operation and there are certain complications. These include:
- Leakage from where the bowel is reconnected, known as an anastomosis
- Blood clots developing post-surgery