Can Constipation Cause Back Pain? Causes, Symptoms and When to See a Doctor
If you have ever felt a dull ache in your lower back while also struggling to have a bowel movement, you may have wondered whether the two problems are connected.
The short answer is yes, constipation can sometimes contribute to back pain, particularly in the lower back, pelvis or tailbone area. However, it is important not to assume that every episode of back pain is caused by constipation.
'Back pain is not the most common sign of constipation, and constipation is not the most common reason for back pain,' says Dr Carmen Fong, double board-certified colorectal surgeon and chief medical officer at Bummed.
Understanding when constipation may be playing a role and when another cause is more likely can help you decide whether simple self-care is enough or whether medical evaluation is needed.
How Common Is Constipation?
Constipation is one of the most common digestive complaints. In the UK, millions of adults experience constipation at some point, and it becomes more common with age.
Doctors generally define constipation as having fewer bowel movements than usual, difficulty passing stools, hard stools, or a feeling of incomplete emptying.
Because constipation is so common and back pain is also extremely common, the two can occur together by coincidence. The challenge is identifying when they are actually related.
How Can Constipation Cause Back Pain?
Several mechanisms may explain the connection.
Bowel Distension and Pressure
When stool remains in the bowel for an extended period, the bowel can become distended. Dr Jay Luthar, instructor in medicine at Harvard Medical School and founder of Lutanen Health, says a distended bowel can place pressure on the lower back and pelvic region, creating a dull aching sensation.
Dr Fong adds that stool retained in the rectum may place mechanical pressure on structures around the sacrum and tailbone.
Muscle Tension From Straining
Repeated straining during bowel movements can tighten the abdominal, pelvic floor, and lower back muscles.
'Straining during bowel movements can create muscle tension that mimics musculoskeletal back pain,' Dr Luthar explains.
Pelvic Floor Dysfunction
Some people with chronic constipation have difficulty relaxing the pelvic floor muscles during a bowel movement. Dr James Lyons notes that pelvic floor dysfunction can both contribute to constipation and create pain or pressure felt in the pelvis or lower back.
What Does Constipation-Related Back Pain Feel Like?
Constipation-related pain tends to have a different pattern from a typical muscle strain.
Common features include:
- A dull ache in the lower back
- Pelvic pressure or heaviness
- Tailbone discomfort
- Bloating or abdominal fullness
- Pain that improves after a bowel movement
Dr Luthar says the discomfort is often diffuse rather than sharply localised.
A less common but recognised condition called proctalgia fugax can cause sudden sharp rectal or pelvic floor muscle spasms that may radiate into the lower back, according to Dr Fong.
How Is It Different From Ordinary Back Pain?
A simple muscle or ligament strain is usually linked to movement.
Musculoskeletal back pain often worsens with:
- Bending
- Lifting
- Twisting
- Prolonged sitting or standing
It is usually not related to bowel habits.
Dr Lyons says that if back pain began after lifting something heavy or changes clearly with position, a musculoskeletal cause is more likely. If the pain is accompanied by several days of bloating, straining, and difficulty passing stool, constipation becomes a more plausible contributor.
Symptoms That Suggest Constipation Is Involved
You are more likely to consider constipation as a contributing factor if you have:
- Infrequent bowel movements
- Hard or difficult-to-pass stools
- Straining during bowel movements
- Abdominal bloating
- Pelvic pressure
- Relief of back pain after passing stool
Dr Fong says that improvement after a bowel movement is one of the strongest clues that constipation is contributing to the discomfort.
What Causes Constipation?
Constipation has many possible causes, including:
- Low fibre intake
- Inadequate fluid intake
- Reduced physical activity
- Changes in routine or travel
- Pregnancy
- Stress
- Pelvic floor disorders
- Certain medications
Dr Lyons highlights opioids, tricyclic antidepressants, antihistamines, and iron supplements as common medication-related causes.
What Can You Do At Home?
For mild constipation without warning signs, conservative measures are often effective.
Increase Fluid Intake
Adequate hydration helps keep stools softer.
Add Fibre Gradually
Dr Luthar recommends increasing fibre slowly rather than suddenly, as a rapid increase can worsen bloating.
Aim for around 25–35 g of fibre per day from foods such as fruit, vegetables, beans, oats, and whole grains.
Stay Physically Active
Walking and other moderate activities can stimulate bowel movement.
Avoid Prolonged Straining
Dr Fong advises limiting toilet sitting time to a few minutes rather than sitting and straining for long periods.
For many people, constipation-related discomfort improves within a few days once bowel function improves.
When Should You See A GP?
Contact your GP if constipation:
- Lasts more than a few weeks
- Keeps coming back
- Is accompanied by persistent back or pelvic pain
- Does not improve with self-care
- Is associated with unexplained changes in bowel habits
Persistent symptoms deserve assessment rather than repeated self-treatment.
Red Flags That Need Urgent Medical Attention
Seek urgent medical care if constipation or back pain is accompanied by:
- Fever
- Persistent vomiting
- Severe abdominal pain
- Blood in the stool
- Black or tarry stools
- Unexplained weight loss
- New leg weakness or numbness
- Loss of bladder or bowel control
- Difficulty urinating
- Numbness around the groin or buttocks ('saddle anaesthesia')
Dr Lyons emphasises that these symptoms require prompt evaluation because they may indicate a more serious abdominal, neurological, or spinal problem.
Could Something Else Be Causing Both Symptoms?
Occasionally, a single underlying condition can cause both constipation and back pain.
Examples include:
- Pelvic masses
- Severe pelvic floor disorders
- Neurological conditions
- Certain spinal disorders
Dr Fong notes that rare conditions, such as a presacral tumour located between the rectum and tailbone, can produce both symptoms and may require imaging for diagnosis.
The Bottom Line
Constipation can sometimes contribute to lower back, pelvic, or tailbone pain through bowel distension, pressure, muscle tension, and pelvic floor dysfunction. The pain is often dull, accompanied by bloating and bowel symptoms, and may improve after a bowel movement.
However, constipation should not automatically be blamed for persistent or severe back pain. Most back pain is still caused by musculoskeletal problems, and ongoing symptoms warrant proper medical assessment.
If you notice back pain alongside constipation, pay attention to the pattern. Relief after passing stool suggests a digestive contribution, while pain that is severe, persistent, associated with movement, or accompanied by red-flag symptoms should be evaluated promptly by a healthcare professional.
Frequently Asked Questions
- Can constipation cause back pain?Yes, constipation can sometimes contribute to back pain, particularly in the lower back, pelvis, or tailbone area.
- What are the symptoms of constipation-related back pain?Symptoms include a dull ache in the lower back, pelvic pressure, tailbone discomfort, bloating, and pain that improves after a bowel movement.
- When should I see a GP for constipation-related back pain?Consult a GP if constipation lasts more than a few weeks, keeps recurring, is accompanied by persistent pain, or does not improve with self-care.
- What are the red flags that need urgent medical attention?Seek urgent care if you experience fever, persistent vomiting, severe abdominal pain, blood in the stool, unexplained weight loss, or new leg weakness.