Chronic Constipation and Chronic Diarrhoea

Written by A/Prof Viraj Kariyawasam, Gastroenterologist

1. What are Chronic Constipation and Chronic Diarrhoea?

Chronic constipation and chronic diarrhoea are common gastrointestinal conditions characterised by persistent changes in bowel habits lasting longer than three months. They may occur as separate conditions or alternate in the same individual.

These symptoms can significantly affect quality of life and may arise from functional gut–brain interaction disorders or underlying gastrointestinal disease.

2. Causes & Risk Factors

From a gastroenterology perspective, chronic changes in bowel habit are approached systematically. The key aims are to distinguish functional conditions from inflammatory, infectious, structural, or malignant causes, and to identify conditions that benefit from targeted treatment.

In constipation, gastroenterologists assess whether symptoms relate to slow movement of stool through the colon, difficulty with evacuation due to pelvic floor dysfunction, or secondary causes such as medications, metabolic disorders, or neurological conditions.

In chronic diarrhoea, important considerations include inflammatory bowel disease, microscopic colitis, coeliac disease, bile acid malabsorption, pancreatic insufficiency, and small bowel pathology. Some conditions cause continuous symptoms, while others fluctuate or are triggered by food or stress.

Chronic constipation may result from slow bowel movement, pelvic floor dysfunction, dietary factors, medications, or disorders of gut–brain interaction.

Chronic diarrhoea may be caused by functional conditions such as IBS, inflammatory bowel disease, coeliac disease, bile acid malabsorption, infections, medication effects, or malabsorption disorders.

3. Symptoms & How They May Present

Symptoms of chronic constipation include infrequent bowel motions, hard stools, straining, a sensation of incomplete evacuation, and bloating.

Symptoms of chronic diarrhoea include frequent loose or watery stools, urgency, abdominal pain, bloating, and sometimes nocturnal symptoms or weight loss.

4. How Are They Investigated?

Investigation depends on age, symptoms, and risk factors.

Gastroenterological assessment focuses on identifying red flags, assessing symptom duration and pattern, and correlating symptoms with blood and stool markers of inflammation, malabsorption, or bleeding.

Colonoscopy is commonly recommended in people over 50, those with alarm features, or those with persistent unexplained symptoms. In selected cases, biopsies are taken even if the bowel looks normal, to diagnose conditions such as microscopic colitis.

Assessment may include blood tests, stool tests, imaging, and endoscopic procedures such as colonoscopy to exclude inflammatory, infectious, or structural causes. Additional specialised tests may be used to assess bowel motility or pelvic floor function.

5. Treatment & Management Options

Management is guided by the underlying cause and symptom severity.

Treatment options may include dietary modification, fibre optimisation, medications to regulate bowel movement, treatment of underlying inflammation or malabsorption, and gut–brain targeted therapies where appropriate.

6. Living With / Managing These Conditions

Chronic constipation and diarrhoea are often long-term conditions that require an individualised management plan.

Education, regular follow-up, and addressing contributing factors such as stress and diet can significantly improve symptom control and quality of life.

7. Prevention & Risk Reduction

Maintaining regular bowel habits, adequate hydration, physical activity, and a balanced diet supports healthy bowel function.

Early investigation of persistent symptoms reduces the risk of missed underlying disease.

8. When to Seek Medical Advice

You should seek gastroenterology review if bowel habit changes are persistent, progressive, or do not respond to initial dietary or medical management.

Early specialist assessment is particularly important if symptoms begin after the age of 50, wake you from sleep, or are associated with iron deficiency anaemia, blood in the stool, unintentional weight loss, or a family history of bowel cancer or inflammatory bowel disease.

Medical review is recommended for persistent constipation or diarrhoea lasting more than a few weeks.

Urgent assessment is required if symptoms are associated with bleeding, weight loss, nocturnal symptoms, iron deficiency anaemia, or a family history of bowel cancer.