The Surprising Link Between Constipation and Back Pain

Here’s what to know about the connection between the two, how to tell whether constipation may be triggering your back pain, and what you can do to feel better.

Constipation and Back Pain: What’s the Link?

Back pain is typically caused by musculoskeletal issues, but constipation can also contribute to back pain, says gastroenterologist Sameer Berry, MD, a clinical assistant professor of medicine at the NYU Grossman School of Medicine in New York City and the chief medical officer of Oshi Health, which provides multidisciplinary gastrointestinal (GI) healthcare.

Because pain signals from the colon enter the spinal cord alongside signals from the lower back and flank, the brain may misinterpret where the discomfort is coming from, says Simon Mathews, MD, a Baltimore-based gastroenterologist and spokesperson for the American Gastroenterological Association, where he chairs the Committee for GI Innovation and Technology.

As stool builds up in the colon, Dr. Mathews says that the stool stretching the walls of the colon can trigger visceral (internal) pain. “The brain sometimes misreads a poorly labeled colon signal as coming from the back. A distended colon can be felt as a dull ache across the low back,” he says.

It’s a vicious cycle, says Joe Betz, a doctor of chiropractic and the president of the International Chiropractors Association, who is based in Boise, Idaho. “Pain can reduce movement, and reduced activity may worsen both spinal stiffness and bowel motility,” he says.

Dr. Betz says that muscle strain, joint irritation, pelvic dysfunction, and prolonged sitting can also cause lower back, flank or pelvic pain that’s often interpreted as related to the digestive system. "Straining during a bowel movement may aggravate an existing back condition without being its original cause,” he says.

Mathews says that people can often point to the specific location of musculoskeletal back pain with one finger. But internal organ pain, also called visceral pain, is associated with a vaguer sense of location. “And it is more likely to be associated with GI symptoms like bloating, fullness, gas, and a sense of incomplete emptying,” he says.

If you’re unsure if your back pain is caused by constipation, or if what you’re doing to manage it is causing constipation, speak to your doctor, Berry says.

How to Manage Lower Back Pain Caused by Constipation

If constipation appears to be contributing to symptoms of back pain, treating the constipation first is the priority, Berry says.

Review Your Medications

Mathews recommends first reviewing your medications with a doctor, especially if they come with side effects like constipation. “Medications get missed most often. If symptoms start within a few weeks of a new prescription, that's the first thing I want to know,” he says.

You may be able to change medications if they trigger constipation, but when that’s not possible, the constipation is treated alongside it, Berry says.

Prioritize Fiber and Hydration

Exercise

People will say they don’t have time for the recommended 150 minutes of cardiovascular exercise weekly, Berry says. He suggests attempting a more realistic goal, even seven minutes a day, if that’s all you have time for. He notes that exercise can alleviate some bloating and abdominal pain in certain people.

Consider a Laxative

Berry says that gastroenterologists will often try lifestyle modifications first, such as having you increase your fiber intake, work at staying hydrated, and engage in daily exercise before trying laxatives, unless you need immediate relief.

Talk to your doctor before starting a laxative. “Laxatives aren’t the answer for everyone. Some people are constipated because the pelvic floor muscles don't coordinate during a bowel movement, and no laxative fixes a coordination problem,” Mathews says.

Treat the Back Pain

When to See a Doctor

• Rectal bleeding or blood in the stool
• Severe abdominal pain
• Unexplained weight loss
• Numbness or weakness in your legs
• Incontinence
• Constipation that lingers beyond a few weeks
• Requiring laxatives more than two or three times a week
  
  

Betz says that symptoms like swelling, constant abdominal pain, vomiting, fever, an inability to pass gas, or saddle-area (inner thigh, groin, or buttock) numbness should prompt medical evaluation instead of assuming that symptoms are musculoskeletal.

Your doctor will take your medical history, prescriptions, and OTC medications into account, Mathews says.