What Are the Different Types of Constipation? Causes and Treatments

Constipation is a common digestive complaint that affects people of all ages. It is generally defined as having fewer than three bowel movements per week and can significantly impact quality of life, causing discomfort, bloating, and difficulty with daily functioning [1]. Constipation may be due to a variety of reasons, ranging from poor dietary habits and lack of physical activity to underlying medical conditions or medication side effects.

Depending on the type of constipation, treatment plans may differ and often include lifestyle changes, such as increasing fibre intake and staying hydrated. Understanding the different mechanisms and types of constipation is key to guiding effective treatment [2]. Let’s explore these types and their specific causes, symptoms, and treatments.

Types of Constipation

Constipation is broadly categorised into primary (functional) and secondary types. The symptoms and management strategies vary depending on the specific type and cause.

1) Primary (Functional) Constipation

Primary or functional constipation is a common digestive problem characterised by infrequent or difficult bowel movements that cannot be fully explained by an underlying medical condition or structural anomaly [2]. Various factors, including a low-fibre diet, inadequate fluid intake, lack of exercise, and certain medications, can contribute to primary constipation. It’s further classified into 3 subtypes:

a) Normal Transit Constipation (NTC)

• This is the most common form of functional constipation.
• The speed of stool movement through the colon (transit time) is considered normal.
• Individuals may still feel bloated, have difficulty with evacuation (dyschezia), or complain of abdominal discomfort.
• Symptoms often overlap with Irritable Bowel Syndrome (IBS-C).

b) Slow Transit Constipation (STC)

• Slow transit constipation is a less common form, mainly seen in middle-aged women.
• People suffering from this type of constipation experience a reduction in colonic motility (peristalsis), meaning the propulsive contractions of the bowels are less frequent or effective.
• Due to this lack of effective peristalsis, food moves more slowly than usual through the digestive tract, and the time it takes for stools to pass through the colon is significantly longer.
• Bowel movements are infrequent, and stools remain in the colon for longer periods, often resulting in a loss of the urge to defecate.

c) Outlet (Defecatory Dysfunction) Constipation

• Outlet constipation occurs when there is a physical or functional problem with the muscles or nerves of the pelvic floor or anal sphincter that prevents the easy passage of stool.
• The person experiences difficulty in passing stools, often described as an inability to expel stool despite the feeling of a full rectum [2].
• Symptoms include excessive straining during bowel movements, a sense of incomplete evacuation, and the need to use manual maneuvers to assist bowel movements.
• A specific form, called dyssynergic defecation, occurs when the anal muscles fail to relax properly or paradoxically contract during a bowel movement.

Treatment for Primary Constipation

Treatment varies by subtype, often beginning with conservative measures.

Treatment for Normal and Slow Transit Constipation

• Dietary and Lifestyle Changes: Increasing your consumption of soluble and insoluble fibre-rich foods like whole grains, fruits, and vegetables to at least 20–35 grams per day [3].
• Increasing water intake to promote softer stools and support fibre’s effect.
• Doing regular physical activity like brisk walking or yoga to help stimulate bowel motility.
• Pharmacological Management: Use of over-the-counter or prescription laxatives (medicines used to relieve constipation) under the guidance of a healthcare provider.

Treatment of Outlet Constipation

• Pelvic Floor Muscle Training (Biofeedback): This is the primary recommended treatment for dyssynergic defecation [2]. A probe is inserted into the anal sphincter by a trained therapist, and visual or verbal feedback is given to the person to help them learn to relax the pelvic floor muscles and coordinate defecation.
• Laxatives: These are often used as an adjunct to biofeedback therapy, not as a primary treatment, and include options like osmotic agents.
• Surgery: In rare, severe cases of outlet constipation, such as those involving significant rectal prolapse or non-responsive dyssynergia, surgery may be considered.

2) Secondary Constipation

Secondary constipation occurs as a symptom or side effect of an underlying medical condition, a specific medication, or a structural obstruction [1].

Causes of Secondary Constipation

The common causes of secondary constipation are:

• Neurological disorders such as multiple sclerosis, spinal cord injury, Parkinson’s disease, or stroke.
• Endocrine or metabolic disorders such as diabetes mellitus, hypothyroidism, hypercalcemia, and pregnancy [1].
• Structural or organic causes, such as colorectal cancer, strictures, or anal fissures.
• Medications, such as opioid pain relievers, tricyclic antidepressants, calcium channel blockers, or iron preparations [3].
• Diet or lifestyle factors, such as chronic low fibre intake, an inactive lifestyle, or dehydration.

Treatment of Secondary Constipation

Effective management focuses primarily on identifying and addressing the root cause, which may involve treating the underlying condition or adjusting medications in consultation with a physician.

Lifestyle and Supportive Management (Must be tailored to the primary cause):

• Hydration: Ensure you drink enough water, as dehydration can contribute to constipation. Aim for at least eight glasses of water per day, or as advised by your doctor [3].
• Fibre: Increase your fibre intake by eating more fruits, vegetables, and whole grains. It acts by adding bulk to your stool and retaining water, which helps it move quickly through your intestines.
• Exercise: Regular physical activity can help stimulate your digestive system. Aim for at least 30 minutes of moderate activity most days of the week.

Nutritional Supplements (Use only after consulting a healthcare provider):

• Magnesium: Magnesium hydroxide (Milk of Magnesia) is an osmotic laxative. While dietary magnesium is important, taking a supplement to treat constipation should be discussed with a doctor, especially for patients with kidney issues.
• Probiotics: Beneficial bacteria called probiotics live in your gut. Consuming probiotics through foods like yoghurt or a probiotic supplement may help with symptoms like bloating and could potentially improve stool frequency in some individuals [4].

Medications for Constipation

There are several types of medications to relieve constipation, which are generally selected based on the severity and specific mechanism of the constipation:

• Bulk-forming Laxatives (e.g., psyllium, methylcellulose): These are often the first-line pharmacologic treatment for functional constipation. They are derived from natural plant fibre and work by absorbing water in the intestine to add bulk to the stool, making it easier to pass. Crucially, they must be taken with ample water to prevent intestinal obstruction [3].
• Stool Softeners (e.g., docusate): These medications act as surfactants, allowing water and fat to penetrate the stool, making its consistency softer and easier to pass.
• Osmotic Laxatives (e.g., milk of magnesia, polyethylene glycol): These agents contain non-absorbable substances that draw water into the colon, which softens the stool and increases bowel frequency. They are generally safe for short-term use but require proper hydration.
• Stimulant Laxatives (e.g., bisacodyl, senna): These work by stimulating the muscles of the intestine to contract, accelerating the passage of stool. Due to the potential for dependency and electrolyte imbalance with chronic use, they are typically reserved for short-term relief or refractory cases [1].
• Prokinetics and Secretagogues (e.g., metoclopramide, linaclotide): These are prescription medications. Prokinetics accelerate gut transit, while secretagogues work by increasing fluid secretion into the small intestine, which softens stool and speeds up transit time [2].
• Surgery: In very rare cases of chronic, severe, and refractory slow transit constipation, surgery to remove part of the dysfunctional colon may be necessary.

Complications of Untreated Constipation

Untreated constipation can lead to various health issues. While occasional constipation is normal, chronic or severe cases can lead to serious issues. Here are some potential complications:

1. Faecal Impaction: Chronic constipation can cause a large, hardened mass of stool to build up in the rectum or colon, which can be challenging to treat and may require medical intervention such as manual disimpaction [1].
2. Haemorrhoids (Piles): When you strain to pass a bowel movement, the veins in the rectum and anus can become swollen and painful, resulting in haemorrhoids.
3. Anal Fissures: Chronic constipation can also lead to small tears in the anus lining, known as anal fissures, which can cause significant pain and bleeding.
4. Rectal Prolapse: Rectal prolapse is a medical condition in which the rectum protrudes through the anus. It can occur when the muscles and ligaments that hold the rectum in place become weakened or damaged.
5. Bladder Dysfunction: Constipation can also put pressure on the bladder, disrupting normal urinary function and potentially leading to urinary frequency or overflow urinary incontinence.

Conclusion

Constipation is a common condition, but understanding its type and cause is essential for effective treatment. Most cases of functional constipation can be effectively managed with consistent lifestyle changes, including increased fibre intake, better hydration, and regular physical activity. In other cases, medications or medical therapies, including specific therapies like biofeedback for outlet constipation, may be necessary.

If you experience persistent, severe, or new onset constipation, consult a healthcare provider immediately to develop a personalised diagnosis and treatment plan.

Frequently Asked Questions (FAQs)

How do doctors treat constipation by type?

Treatment of constipation varies by type. Normal and slow transit functional constipation may be managed with dietary changes and laxatives. Outlet (defecatory dysfunction) constipation is primarily treated with biofeedback therapy. Secondary constipation requires treating the underlying cause first.

How can I tell which type of constipation I have?

Self-diagnosis is difficult and should be confirmed by a doctor. Generally, Normal Transit involves regular movements but with straining/incomplete evacuation. Slow Transit causes infrequent stools (less than 1-2 per week). Outlet constipation involves difficulty or inability to expel stool despite the urge to do so.

What is the most serious form of constipation?

Any form of constipation due to an obstruction (e.g., colorectal cancer, stricture) or resulting in acute faecal impaction is medically serious. Obstructive defecation, especially due to severe rectal prolapse or pelvic dysfunction, is serious as it may cause significant complications and often requires specialist intervention.

What is the most common cause of constipation?

The most common form of constipation is Primary (Functional) Constipation (also called idiopathic constipation). It is often caused by a combination of lifestyle factors such as a low-fibre diet, insufficient fluid intake, or a lack of physical activity, rather than any underlying medical condition.

What causes slow transit constipation?

Slow transit constipation happens when the colon’s natural muscle movement (peristalsis) is impaired, causing stool to move slowly. While sometimes idiopathic (unknown cause), common factors can include neurological issues affecting the colon’s nerves, certain medications, or chronic low fibre intake and dehydration.

Disclaimer: This article is for informational purposes only and is based on general medical understanding and published literature. It is not a substitute for professional medical advice, diagnosis, or treatment. Please consult a healthcare provider before beginning any new wellness practice, especially if you have an existing medical condition or are on medication.

References

[1] Jani, B., & Marsicano, E. (2018). Constipation: Evaluation and Management. Missouri Medicine, 115(3), 236–240. https://pmc.ncbi.nlm.nih.gov/articles/PMC6140151/

[2] Kang, S. J., Cho, Y. S., Lee, T. H., Kim, S.-E., Ryu, H. S., Kim, J.-W., Park, S.-Y., Lee, Y. J., & Shin, J. E. (2021). Medical Management of Constipation in Elderly Patients: Systematic Review. Journal of Neurogastroenterology and Motility, 27(4), 495–512. https://doi.org/10.5056/jnm20210

[3] American College of Gastroenterology (ACG). (2022). ACG Clinical Guidelines: Management of Constipation in Adults (Abridged). American Journal of Gastroenterology**, ** 117**(12), ** 1923–1934**.** https://journals.lww.com/ajg/Fulltext/2022/12000/ACG_Clinical_Guidelines__Management_of.4.aspx

[4] Araújo, M. M., & Botelho, P. B. (2022). Probiotics, prebiotics, and synbiotics in chronic constipation: Outstanding aspects to be considered for the current evidence. Frontiers in Nutrition, 9. https://doi.org/10.3389/fnut.2022.935830