Can constipation cause lower back pain? Gastroenterologist explains the link and shares warning signs you should not ignore

Constipation may indirectly trigger lower back pain through straining, bowel distension, prolonged toilet sitting, or pelvic floor dysfunction.

Lower back pain is tied to posture-related problems, especially when you spend long hours sitting at a desk. But if you are also struggling with constipation, could the two be connected? After all, you are straining for long time in washroom when constipated. But a gastroenterologist unveiled a layered reasoning for this doubt.ALSO READ: Acidity and bloating keep coming back? Surgeon shares good gut health habits and 6 signs to see a doctor

Dr Santhosh Rajendran, junior consultant in gastroenterology at SIMS Hospital, Chennai, revealed that constipation may indirectly contribute to lower back pain in some cases. However, experiencing both symptoms does not necessarily mean one is causing the other.

How can constipation contribute to lower back pain?

While the doctor clarified that the cause-and-effect relationship is indirect, he revealed a possible chain of events linking constipation to lower back pain.

He clinically described, “The mechanism that is understood is usually because of referred visceral pain. The afferents from the distal colon usually enter the spinal cord around the thoracic region and the sacral region, and the viscerosomatic convergence means colonic distension is felt in the lumbosacral region.”

The gastroenterologist further explained that severe constipation can cause a build-up of stool that stretches the lower bowel and presses on nearby structures. This may produce pain resembling sciatica, which can improve once the impacted stool is removed.

Posture and straining also factor in. Prolonged sitting on the toilet in a slouched position can place additional stress on the lower back, while repeated straining increases pressure within the spinal discs. The doctor clarified that this may aggravate an existing disc problem rather than cause a new one.

Lastly, pelvic floor dysfunction may link the two symptoms. The doctor described that these muscles help coordinate bowel movements and support stability around the pelvis and lower back. When they do not work together properly, they can be one of the contributing factors of constipation and may also be associated with lower back pain.

When you keep straining, your pelvic floor may be in trouble.

Does having both symptoms mean constipation is the cause?

Now, the doctor cautioned against assuming that constipation is the cause of the back pain if you have these two symptoms at the same time. The relationship can also be the opposite, or both symptoms may share an underlying cause. The gastroenterologist flagged conditions such as hypothyroidism, diabetes, Parkinson's disease, and spinal disorders, as well as pregnancy, as possible contexts in which the symptoms may coexist.

“Association here tells you very little about causation, ” he added.

So, constipation may be indirectly connected to back pain in some cases, but it is not the only reason.

Warning signs you should not ignore

Dr Rajendran highlighted that new bowel dysfunction alongside back pain should not automatically be dismissed as simple constipation, especially when these signs also show:

• Numbness around buttocks, inner thigh areas, known as saddle anaesthesia
• Difficulty passing urine or an inability to empty the bladder
• Pain, weakness or numbness affecting both legs

These symptoms can indicate cauda equina syndrome, a serious condition involving compression of nerves in the lower spine that requires medical assessment. A physician conducts an examination to check anal muscle tone.

Constipation-related straining may contribute to lower back pain; the link is indirect. Sometimes, bowel symptoms and back pain occurring together may point to a shared underlying problem. Relieving constipation may therefore not always resolve your back pain.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.