Constipation and Lower Back Pain – The Gut-Spine Connection Explained

Constipation and lower back pain are two of the most common physical complaints in adults, and they share a closer biological relationship than most people realise. When the large intestine becomes distended with stool, the resulting pressure, postural compensation, and nerve irritation can directly contribute to lower back pain and tension. 

At the same time, not all lower back pain occurring alongside constipation has a gut-related cause — and in some cases, the two symptoms point to something that warrants medical attention rather than soft tissue treatment. 

This article explains the three mechanisms by which constipation can cause lower back pain, how to distinguish gut-related back pain from mechanical or red-flag presentations, and where hands-on therapy for lumbar tension fits within the broader picture.

Key Takeaways

• Constipation can cause lower back pain through three distinct mechanisms: direct pressure from a loaded large intestine, tension in the psoas major muscle, and referred pain via shared lumbar nerve pathways. 
• The relationship is sometimes bidirectional — a sedentary lifestyle and chronic pain can both worsen constipation, creating a cycle that reinforces both conditions. 
• Several symptoms occurring alongside back pain and constipation are red flags that require GP assessment, not massage or self-treatment 
• Myotherapy addresses the lumbar muscle tension component of constipation-related back pain, but resolving the back pain fully depends on addressing the underlying bowel issue first.

Can Constipation Really Cause Lower Back Pain?

Constipation is a gastrointestinal condition characterised by infrequent bowel movements — typically fewer than three per week — along with hard or difficult-to-pass stools, abdominal distension, and a sense of incomplete emptying. According to Better Health Channel, constipation is one of the most common digestive complaints in Australia, with causes ranging from low dietary fibre intake, insufficient water consumption, and a sedentary lifestyle through to medications, irritable bowel syndrome, and underlying neurological conditions.

The short answer to whether constipation can cause lower back pain is: yes, through several well-established mechanisms. The lower back and the gastrointestinal tract share anatomical proximity, nerve supply overlap, and a key muscle — the psoas major — that connects them directly. When the bowel becomes significantly loaded, these shared structures transmit the consequences into the lumbar region.

Three Mechanisms Linking Constipation to Lower Back Pain

1. Direct Pressure from the Large Intestine

The large intestine — specifically the descending colon, sigmoid colon, and rectum — sits in proximity to the lumbar spine and the structures surrounding it. When stool accumulates and normal bowel movements become infrequent, the bowel becomes distended and exerts pressure on surrounding tissues, including the lumbar nerves and soft-tissue structures of the lower back.

This pressure can produce a dull, diffuse ache across the lower back area that does not follow the typical pattern of a musculoskeletal injury. It tends to fluctuate with bowel fullness, often worsening before a bowel movement and easing once constipation is resolved. In cases of severe constipation or fecal impaction — where stool becomes hardened and compacted in the rectum — this pressure can become significant enough to cause persistent low back pain that does not respond to soft tissue treatment until the underlying bowel issue is addressed.

2. The Psoas Major: The Gut-Spine Bridge

The psoas major muscle is the primary anatomical connection between the gut and the spine. The psoas major attaches to the lumbar vertebrae and runs through the posterior abdomen alongside the digestive organs before connecting to the femur. It is both a hip flexor and a lumbar stabiliser — and its position means it is directly influenced by abdominal bloating, bowel distension, and the postural changes that accompany chronic constipation.

When abdominal pressure increases due to a loaded bowel, the psoas major responds by tightening—a protective response that loads the lumbar spine. Over time, sustained psoas major tension produces low back pain, hip flexor tightness, and a characteristic forward-lean posture that many people with chronic constipation adopt unconsciously. Myofascial trigger points in the psoas major can refer pain directly into the lower back, making the gut origin of the problem easy to miss. Understanding how myofascial pain syndrome produces these deceptive referred patterns is central to accurately assessing this type of presentation.

3. Referred Pain via Shared Nerve Pathways

The nerves supplying the lower back and the gastrointestinal tract overlap through the lumbar spinal segments. When the bowel generates significant sensory input — through distension, cramping, or inflammation — the brain can interpret some of that signal as coming from the lower back rather than the gut. This visceral referred pain mechanism is the same process that makes kidney problems feel like back pain and gallbladder issues produce right shoulder blade pain.

Referred pain from constipation tends to be poorly localised — a vague, deep ache around the lower back and sometimes the sacral region — rather than the sharp, localised pain more typical of a disc or joint problem. The sacral and sacroiliac joint region is a common area where gut-referred pain and mechanical pain overlap and are easy to confuse. It does not follow a dermatomal pattern and typically does not worsen with specific spinal movements.

When Back Pain and Constipation Together Are a Red Flag

This is the most important section of this article. While constipation commonly contributes to lower back pain through the mechanisms above, some combinations of back pain and bowel change signal conditions that require urgent medical assessment, not massage or home management.

See a GP promptly if back pain and constipation occur alongside any of the following:

• Unexplained weight loss — a combination of back pain, constipation, and weight loss warrants investigation to rule out a neoplasm or other serious underlying cause 
• Blood in the stool — this is always a reason to seek medical assessment 
• Fever or night sweats — may indicate infection or inflammatory bowel disease
• Neurological symptoms — weakness, numbness, or tingling in the legs occurring alongside bowel change can indicate spinal cord involvement, including a spinal tumour or neurogenic bowel dysfunction. 
• Incontinence — new onset fecal incontinence alongside back pain is a potential sign of cauda equina syndrome, which is a medical emergency 
• Back pain that is constant, severe, and unrelated to movement — particularly in older adults- requires investigation. 
• Constipation that is sudden, severe, and uncharacteristic — particularly if accompanied by abdominal pain and vomiting, as this may indicate bowel obstruction

If any of these features are present, do not proceed with soft tissue treatment. See a GP first. The information in this article applies to functional constipation-related back pain in otherwise healthy adults — it is not a framework for self-diagnosing or self-treating the presentations above.

Which Comes First: The Constipation or the Back Pain?

The relationship between constipation and lower back pain is sometimes bidirectional. Constipation can cause or contribute to lower back pain, but chronic back pain and a sedentary lifestyle can also contribute to constipation.

Chronic pain reduces physical activity. A sedentary lifestyle slows gastrointestinal motility and contributes to infrequent bowel movements. Pain-relief medications — particularly opioids — are a well-known cause of constipation. Postural changes adopted to guard against back pain can compress the abdomen and interfere with normal defecation mechanics.

This cycle — where back pain worsens constipation and constipation worsens back pain — is one reason chronic lower back pain can be so persistent. Breaking it requires addressing both ends: resolving the bowel issue through diet, hydration, physical activity, and, where appropriate, over-the-counter management or medical guidance; and addressing the secondary lumbar tension and psoas major tightness through hands-on treatment.

Constipation-Related Back Pain vs Mechanical vs Red Flag: A Clinical Comparison

How Myotherapy Addresses the Lumbar Tension Component

Once a red-flag presentation has been ruled out and the underlying bowel issue is being managed, myotherapy can meaningfully address the soft-tissue consequences of constipation-related back pain — specifically, the psoas major tension, lumbar muscle guarding, and trigger-point activity that develop in response to chronic gut pressure.

At Surf & Sports Myotherapy in Noosaville, assessment of lower back pain always considers the full picture — including posture, hip flexor tightness, and any patterns that suggest a visceral or systemic contribution to the presentation. Treatment may include:

• Psoas major and iliacus release — addressing the hip flexor tension that develops in response to abdominal loading and altered posture 
• Lumbar soft tissue work — treating the paraspinal and quadratus lumborum tightness that accumulates through protective muscle guarding; for a fuller look at how remedial massage addresses chronic lower back pain, that article covers the hands-on approach in more detail 
• Trigger point therapy — deactivating myofascial trigger points in the lumbar region and posterior hip that produce and maintain the referred pain pattern 
• Thoracolumbar fascial release — addressing the connective tissue tension that connects the posterior abdominal wall to the lumbar spine

It is important to understand the limits of this approach: myotherapy addresses the musculoskeletal consequences of constipation-related back pain. If the constipation itself is not resolved, the lumbar tension and psoas major tightness will return. Soft tissue treatment works best alongside active management of the bowel issue, not instead of it.

From the Clinic, “Lower back presentations don’t always come from the back. When a patient’s pain is diffuse, doesn’t follow a clear movement pattern, and seems to fluctuate without an obvious physical cause, the abdomen — and particularly the gut — is always worth considering. The psoas major is often where the two systems meet clinically. When it’s holding tension from a chronically loaded bowel, no amount of lumbar work alone will fully resolve the pain.”

For a broader understanding of how referred pain operates — including how internal organs produce pain in locations that seem entirely unrelated to the source — the team’s guide on referred pain and symptom confusion covers the neurological and clinical basis in full detail.

Managing Constipation to Relieve Back Pain: Where to Start

Addressing the bowel side of this equation is outside the scope of myotherapy, but there are well-established first-line approaches worth being aware of. The Better Health Channel’s guide to constipation outlines evidence-based first-line management, which consistently centres on:

• Dietary fibre — increasing intake from vegetables, legumes, and whole grains supports regular bowel movements
• Hydration — adequate daily water intake is one of the simplest and most effective ways to support healthy digestion
• Physical activity — regular movement stimulates gastrointestinal motility; a sedentary lifestyle is a consistent contributor to chronic constipation
• Routine — consistent toilet habits and not suppressing the urge to defecate support regularity

Over-the-counter options, including bulk-forming laxatives and osmotic agents such as macrogol, are commonly used for short-term relief of constipation. If constipation is persistent or worsening, or accompanied by any of the red-flag symptoms listed above, a GP assessment is the appropriate next step rather than continued self-management.

For the musculoskeletal side, a myotherapy assessment at Surf & Sports Myotherapy can clarify the extent to which psoas major tension and lumbar muscle guarding contribute to the pain and establish a treatment plan accordingly.

Frequently Asked Questions

How do I know if my lower back pain is from constipation? 

Constipation-related lower back pain tends to be dull, diffuse, and poorly localised — it does not typically follow the sharp or movement-specific pattern of a musculoskeletal injury. It often fluctuates alongside bowel fullness, worsening when constipation is at its worst and easing when normal bowel movements resume. If you are unsure whether your back pain has a bowel component, a GP assessment can help identify or rule out contributing causes.

Will treating my constipation get rid of the back pain? 

In many cases, yes — if constipation is the primary driver of the back pain. Once normal bowel movements resume and abdominal pressure reduces, the referred pain and psoas major tension often ease significantly. However, if lumbar muscle guarding and trigger point activity have been present for some time, soft-tissue treatment may be needed to fully resolve residual tension, even after the constipation is addressed.

Can back pain cause constipation? 

Yes. Chronic back pain contributes to reduced physical activity, postural changes that compress the abdomen, and, in some cases, medication use — all of which can slow gastrointestinal motility and contribute to constipation. For a deeper look at how back pain and sciatica are assessed and managed at the clinic, see that article, which covers the full mechanical picture. The relationship between constipation and back pain is often bidirectional, particularly in people with chronic pain.

Is it safe to have a remedial massage when I have back pain and constipation? 

In most cases, yes — provided the red flag symptoms listed in this article are not present. If the back pain and constipation are functional, soft-tissue treatment for the lumbar tension component is appropriate. If you have any of the red-flag features — neurological symptoms, unexplained weight loss, fever, blood in stool, or new-onset incontinence — seek a GP assessment before any manual therapy.

When should I see a doctor instead of a myotherapist for back pain and constipation? 

See a GP first if the back pain is constant and severe regardless of position or movement, if bowel or bladder function has changed alongside the back pain, if you have experienced unexplained weight loss, or if you have any neurological symptoms such as leg weakness or numbness. These features can indicate conditions requiring medical investigation that are outside the scope of myotherapy. For back pain that is clearly mechanical or soft tissue in nature — occurring alongside constipation without any of the above features — a myotherapy assessment is a reasonable starting point.

Back Pain With a Gut Component Needs a Different Approach

Constipation-related lower back pain is a real and common presentation — but it requires a broader lens than a purely musculoskeletal problem. Understanding the gut-spine connection means addressing both ends: managing the bowel issue through lifestyle, diet, and, where necessary, medical support; and treating the secondary lumbar tension and psoas major tightness that develop in response to chronic gut pressure.

If you are dealing with lower back pain on the Sunshine Coast and are not sure whether the gut is playing a role, the team at Surf & Sports Myotherapy in Noosaville can help assess the musculoskeletal picture and direct you appropriately.

Book your appointment online or call 0423 729 694.

Opening hours: Monday–Friday 08:00–19:00 | Saturday 08:00–16:00 Location: 3/14 Thomas St, Noosaville QLD 4566

About the Author

Gary Javonena is the founder of Surf & Sports Myotherapy and holds an Advanced Diploma of Myotherapy from RMIT University.

Gary’s clinical work includes the assessment of complex musculoskeletal presentations in which referred pain, postural dysfunction, and systemic contributors intersect — including cases in which gastrointestinal function directly contributes to lumbar pain patterns. Meet the full team.