An expert has issued a warning about a “subtle” symptom of cancer that could suggest “internal bleeding”. This easily overlooked sign might point to one of the UK’s deadliest cancers.

According to Cancer Research UK, there are approximately 44,000 new cases of bowel cancer each year in the UK, ranking it as the fourth most common cancer. It is also the second deadliest, causing around 16,800 deaths annually.

Also known as colorectal cancer, it typically manifests with symptoms related to changes in bowel habits. However, there are more “subtle” indicators to be vigilant for.

In a conversation with Express.co.uk, Dr Robin Clark, the medical director at Bupa Health Insurance, highlighted that patients with bowel cancer may suffer from anaemia due to internal bleeding, often from the tumour itself.

Dr Clark advised: “There are several more subtle symptoms to look out for. A diagnosis of anaemia may be a sign that you’re bleeding internally, even if you haven’t noticed blood in your poo.”

“The lack of iron in the body can leave you feeling tired.” Anaemia is generally identified through a blood test once symptoms become noticeable.

Symptoms of anaemia to be aware of include shortness of breath, noticeable heartbeats (heart palpitations), and pale skin. According to an expert, another sneaky symptom is weight loss.

Dr Clark elaborated: “Weight loss is less common than some of the other symptoms, but bowel cancer can prevent you from being able to absorb all the nutrients from your food. You might not feel like eating if you feel sick, bloated or if you just don’t feel hungry.”

Early symptoms

The earliest signs of bowel cancer usually manifest in the toilet, warned Dr Clark. He cautioned that the disease could cause changes to your stools in its initial stages.

“Changes in the colour, shape, and texture of your poo that last longer than a few days can reveal signs of infection, digestive issues or more serious problems, such as cancer,” he stated.

“Although persistent constipation can be a sign of bowel cancer – having looser stools or feeling the need to go to the toilet more frequently is a more common symptom. Other symptoms can include bloating, abdominal pain or mucus in the poo.”

He stressed the importance of monitoring any changes to your bathroom habits and consulting a medical professional if necessary. “Though your toilet habits might make you feel uncomfortable, being in tune with your bowels could be a life saver,” said Dr Clark.

“The most common things to look out for are changes to your toilet habits or poo. If you have black or dark red poo, or bloody diarrhoea, you should see your GP urgently.”

He emphasised the gravity of recognising early signs, saying: “Bowel cancer is one of the most common cancers, so it’s vital to speak to a medical professional if you notice symptoms. If anything doesn’t look or feel right, or you’ve noticed an unexplained change of some sort, it’s crucial that you seek medical help immediately, no matter what your age.”

The NHS also lists abdominal pain triggered by eating, nausea, and persistent abdominal swelling as potential indications of bowel cancer. Anyone experiencing these should consult their GP without delay.