Constipation: Causes, Symptoms and Treatment

What is Constipation?

Constipation is a common digestive complaint in which a person has fewer than three bowel movements per week, passes hard or dry stools, or experiences straining and discomfort during defecation. It is not a disease in itself but rather a symptom that can result from a wide range of underlying causes. Constipation affects people of all ages but is particularly common in older adults, pregnant women, and individuals with a sedentary lifestyle.

Causes

The causes of constipation can be divided into functional and organic categories:

Common Functional Causes

• Low-fiber diet: Insufficient intake of fruits, vegetables, and whole grains slows bowel movements.
• Inadequate fluid intake: Not drinking enough water leads to hard, dry stools.
• Physical inactivity: Lack of exercise reduces intestinal motility.
• Suppressing the urge to defecate: Repeatedly ignoring the urge can disrupt normal bowel function.
• Stress and psychological factors: Emotional stress can negatively affect the digestive system.
• Irritable bowel syndrome (IBS): A functional gut disorder that can present with constipation.

Medication-Related and Organic Causes

• Medications: Opioids, antidepressants, calcium-containing antacids, and certain blood pressure drugs can cause constipation.
• Hypothyroidism: An underactive thyroid slows metabolism and gut motility.
• Diabetes mellitus: Can impair the nerve supply to the intestines.
• Bowel obstruction or narrowing: Structural abnormalities can block stool passage.
• Parkinson's disease and other neurological conditions: Affect intestinal motility through the nervous system.
• Pregnancy: Hormonal changes and pressure from the growing uterus slow bowel function.

Symptoms

Common signs and symptoms of constipation include:

• Fewer than three bowel movements per week
• Hard, lumpy, or dry stools
• Straining during defecation
• A feeling of incomplete emptying after a bowel movement
• Abdominal pain, bloating, and a sensation of pressure in the lower abdomen
• Nausea and general discomfort

In chronic constipation, these symptoms can persist for weeks or months and significantly affect quality of life.

Diagnosis

Constipation is primarily diagnosed through a thorough medical history and physical examination. The healthcare provider will ask about stool frequency, consistency, and any associated symptoms. The Bristol Stool Form Scale is commonly used to assess stool consistency.

If symptoms are persistent or unexplained, further investigations may be needed:

• Blood tests: To rule out thyroid disorders, diabetes, or other underlying conditions.
• Colonoscopy: To examine the bowel lining and exclude polyps, tumors, or inflammatory changes.
• Imaging: Abdominal ultrasound or X-ray if structural causes are suspected.
• Colonic transit time study: Measures how quickly material moves through the colon.

Treatment

Treatment depends on the underlying cause and severity of constipation. In most cases, simple lifestyle changes can bring significant relief.

General Measures

• High-fiber diet: Whole grains, legumes, vegetables, and fruits support bowel function. A daily intake of at least 25-30 g of fiber is recommended.
• Adequate hydration: Drink at least 1.5 to 2 liters of water or unsweetened beverages per day.
• Regular physical activity: Even daily walking can stimulate intestinal movement.
• Regular toilet routines: Taking time to use the toilet after meals takes advantage of the natural digestive reflex.

Medication Treatment

When lifestyle changes are insufficient, laxatives may be used. Different types work through different mechanisms:

• Osmotic laxatives (e.g., macrogol, lactulose): Draw water into the bowel to soften stools.
• Stimulant laxatives (e.g., bisacodyl, sodium picosulfate): Stimulate the intestinal muscles to contract.
• Bulk-forming agents (e.g., psyllium husk, wheat bran): Increase stool volume and encourage bowel movement.
• Lubricant laxatives (e.g., mineral oil): Help stools pass more easily through the intestine.

Important: Laxatives should only be used short-term and under medical supervision, as prolonged use can lead to dependency.

Treatment for Chronic Constipation

Chronic constipation may require a thorough evaluation and a long-term management strategy, which can include biofeedback therapy, pelvic floor rehabilitation, or prescription medications such as prucalopride or linaclotide.

When to See a Doctor

Medical attention should be sought in the following situations:

• Blood in the stool or black, tarry stools
• Unintentional weight loss
• Constipation lasting longer than three weeks
• Severe abdominal pain or vomiting
• A sudden change in bowel habits without apparent reason
• Constipation in infants or young children

References

1. German Society of Gastroenterology, Digestive and Metabolic Diseases (DGVS): Clinical Guideline on Chronic Constipation, AWMF Registration No. 021-019 (2022).
2. World Gastroenterology Organisation (WGO): Global Guidelines on Constipation – A Global Perspective (2010, updated 2023).
3. Müller-Lissner S. et al.: Myths and Misconceptions About Chronic Constipation. American Journal of Gastroenterology, 100(1):232-242 (2005).