This means being aware of the potential warning signs, and getting them checked out sooner rather than later, really can make the world of difference. Although the disease mostly affects people aged 50-plus - bowel cancer is everyone's business.
Consultant colorectal surgeons Mr Colin Elton and Mr Daren Francis highlight seven key warning signs of bowel cancer that everybody should be aware of.
The main message? These symptoms don't automatically mean you have cancer and are usually caused by something far less serious - but it's always best to get them checked by your doctor quickly.
1. Blood in your stools
Perhaps the most well-known symptom of bowel cancer is bleeding from the bottom or blood in the stools, which can vary from a small amount on the tissue after you wipe, to a substantial amount mixed in with your stool.
"Bowel cancer can start in the large bowel (colon) or back passage (rectal)," explains Elton. "Usually, bright red blood indicates bleeding in the lower colon or rectum, while darker red blood is a sign of bleeding in the small bowel or upper colon. If you notice any bleeding, book an appointment with your doctor so they can give you an examination and find out what's causing it."
There are many other possible reasons for rectal bleeding, such as haemorrhoids, fistulas, fissures, diverticulitis, Crohn's disease, ulcerative colitis, gastroenteritis, a sexually-transmitted infection or polyps. "Even though bowel cancer may not be the cause, it's important to visit your GP or a doctor if you're experiencing the symptom - just to be sure," Elton advises.
2. Change in bowel habits
"Although usually a symptom of other less serious problems, persistent constipation, diarrhoea and bowel incontinence could also be a sign of bowel cancer. It's important to tell your GP if you've noticed these changes in your bowel habits, especially if you're also experiencing bleeding from your back passage," says Francis.
A more common cause of changing bowel habits is irritable bowel syndrome (IBS), "Your symptoms are far more likely to be caused by this," adds Francis, "but it's always important to check with a specialist, just to be on the safe side.
Fatigue is a symptom of most cancers, including bowel cancer. But as most people experience some degree of fatigue due to their busy lifestyles, it can be a difficult symptom to spot. "Cancer fatigue isn't like ordinary tiredness," explains Elton. "It doesn't tend to improve after a good night's sleep or a cup of coffee, and it's often described as 'whole body tiredness'. In some cases, it's been known to affect an individual's ability to participate in normal activities."
He stresses that anyone concerned by the level of exhaustion they're feeling despite getting lots of rest, should seek medical advice to investigate the cause.
4. Unexpected weight loss
Like fatigue, unexpected weight loss is a generic cancer symptom seen in a lot of cancer cases. Francis says: "When you lose a substantial amount of weight for no apparent reason, you're experiencing unexplained weight loss. For example, if you lose 10 or more pounds and can't understand why, this would be considered a concern. Usually, if you're experiencing a change in bowel habits, blood in the stool, or pain in the abdomen along with unexplained weight loss, this could be an indication of bowel cancer - so it's important to pay attention to your body and keep an eye on any changes that might be occurring."
5. Lumps and bumps
Elton says some bowel cancer patients may notice an unusual lump or bump in their abdomen or back passage, often caused by the cancer tumour. "See your GP if any lumps don't go away or if they're affecting how you sleep or eat, as this could be a sign bowel cancer is present," he says.
6. Abdominal pain or discomfort
Abdominal pain, bloating, gas, indigestion or general stomach pain are very common, and are usually a reflection of your diet. Francis says symptoms that occur occasionally, for example fewer than twice a week, and easily respond to over-the-counter medication are rarely a cause for concern.
"But if you've noticed these symptoms on a more frequent or severe basis - for example, consistently waking you up at night or causing you to use over-the-counter medications more than twice a week - you should pay your GP a visit, as it could be a sign of bowel cancer," he says, explaining that the symptoms may occur if bowel cancer tumours block part of the bowel and cause disruptions to the digestive system.
7. Nausea and vomiting
If nausea or vomiting is accompanied by any of the other bowel cancer symptoms, this could potentially be a sign of bowel cancer, usually because the cancer tumour is causing a bowel obstruction.
"Depending on the size and severity of the tumour blockage, solids, liquids and even gas may be prevented from passing through the colon," says Elton. "This can lead to painful stomach cramps and constipation, and, in turn, nausea and vomiting."