When Do Changes in Bowel Habits Require Further Testing?

What Are Considered Changes in Bowel Habits?

Bowel habits can vary from person to person, so what is “normal” differs for each individual. In general, a change in bowel habits refers to a noticeable and sustained difference from your usual pattern. This may involve how often you pass stools, how they look or how you feel during bowel movements.

• Frequency: Passing stools less often than usual, such as fewer than three times a week, may indicate constipation. On the other hand, having loose or watery stools more frequently than normal may suggest diarrhoea.
• Consistency: Changes in stool form, such as harder, lumpy stools or consistently loose stools, can signal alterations in how your digestive system is functioning.
• Changes in colour or appearance: Stools may vary in colour depending on diet, but certain changes can be significant. For example, black stools may indicate bleeding in the upper digestive tract, while bright red blood may come from the lower bowel. Pale or clay-coloured stools may point to issues with bile flow.
• Urgency or retention: A sudden need to rush to the toilet or the sensation of not fully emptying your bowels can also be considered a change in bowel habits. These symptoms may be associated with conditions affecting the colon or rectum.

What Causes Changes in Bowel Habits?

There are many possible reasons for changes in bowel habits. These causes range from temporary lifestyle factors to conditions affecting the structure or function of the digestive tract.

• Dietary changes: A sudden increase or decrease in fibre intake, dehydration or consuming certain foods can affect bowel movements.
• Lifestyle factors: Newly introduced stress, lack of physical activity and disruptions to routine, such as travel, can impact gut function.
• Medication: Some medications, including antibiotics, iron supplements and certain painkillers, may cause constipation or diarrhoea.
• Infections: Bacterial, viral or parasitic infections can lead to temporary changes in bowel habits, often accompanied by other symptoms like fever or abdominal discomfort.
• Functional gastrointestinal conditions: Conditions such as irritable bowel syndrome (IBS) can cause ongoing changes in bowel habits without structural abnormalities.
• Inflammatory or structural conditions: More serious causes include inflammatory bowel disease (IBD), bowel polyps or colorectal cancer, which may present with persistent changes and other warning signs. These conditions could cause obstructions or make it painful to pass motion.

Alarming Signs and Symptoms

It can often be difficult to tell the difference between routine, explainable changes and symptoms of more serious conditions. Some of the most noticeable changes include:

Blood in the Stool

Seeing blood in your stool should always be taken seriously. This may appear as bright red blood, darker maroon stools or black, tarry stools. While minor causes such as haemorrhoids are common, bleeding can also be linked to more serious conditions such as colorectal cancer or inflammatory bowel disease. Generally, darker stools are a sign of bleeding further within the intestinal tract, while bright red blood could be caused by bleeding closer to the rectum or anus.

Persistent Pain or Discomfort

Experiencing pain when passing stools is not something to ignore, especially if it happens repeatedly. This pain may be sharp, burning or tearing in nature, and can occur during or after a bowel movement.

Common causes include conditions such as anal fissures, which are small tears in the lining of the anus, or haemorrhoids, which can become inflamed and painful. Constipation and passing hard stools are frequent contributing factors.

Ongoing abdominal pain, cramping or bloating that does not resolve can also indicate inflammation, obstruction or other issues within the digestive tract.

Narrow or Pencil-Thin Stools

Stools that become consistently thinner than usual may indicate a narrowing in the colon, which points to a possible obstruction affecting how stool passes through the bowel.

In some cases, this may be associated with conditions such as colorectal polyps or tumours, which can partially block the passage of stool. If this change is ongoing or occurs together with other symptoms such as bleeding, abdominal pain or changes in bowel frequency, further medical evaluation is recommended.

When Should You See a Doctor for Further Testing?

You should consider seeing a doctor if:

• You experience symptoms that persist for a few weeks: Changes that do not resolve within 2–4 weeks, keep recurring or worsen may require further assessment.
• You experience red-flag symptoms: The symptoms listed above, such as blood in the stool and persistent pain, should be promptly evaluated, as they are more immediately obvious signs of potential conditions.
• Age considerations are present: Individuals aged 45 and above are at higher risk of colorectal conditions and should be more vigilant about new or persistent changes. If you fall within this age range, symptoms should not be ignored.
• You have a family history of colorectal issues: Having a family history of colorectal issues, such as cancer or polyp growth, may point to you having a higher risk of developing these issues.

Testing and Monitoring

If further evaluation is needed, your doctor may recommend a combination of tests depending on your symptoms, medical history and risk factors.

• Stool tests: These are often used as an initial step to detect infections, inflammation or hidden (occult) blood in the stool.
• Blood tests: Blood tests can help identify signs of chronic blood loss, infection or inflammation within the body.
• Colonoscopy: A colonoscopy allows direct visualisation of the colon and rectum using a flexible camera. It is one of the most comprehensive tests and enables the doctor to detect abnormalities, take biopsies or remove polyps if needed.
• CT colonography or imaging: Imaging tests such as CT colonography may be used as an alternative or complementary investigation to assess the structure of the colon and surrounding organs.

Potentially Serious Causes Your Doctor May Detect

In some cases, changes in bowel habits may be linked to more serious underlying conditions that your doctor may be able to detect during a screening.

• Colorectal cancer: Colorectal cancer is one of the most important conditions to identify early, especially in individuals with persistent symptoms or risk factors.
• Colorectal polyps: Colorectal polyps are growths in the colon that may develop into cancer over time if left untreated.
• Inflammatory bowel disease (IBD): Inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis can cause ongoing inflammation, leading to changes in bowel habits and other symptoms.
• Bowel obstruction: This occurs when there is a partial or complete blockage in the intestine, which can affect stool passage and cause pain, bloating and altered bowel habits.
• Chronic gastrointestinal bleeding: This refers to ongoing, sometimes unnoticed bleeding in the digestive tract, which can lead to anaemia and related complications.