Bloating and lower back pain often show up together because the intestines, kidneys, and pelvic organs sit close to the lower back, so pressure in one area can be felt in the other. Most of the time this combination comes from gas, constipation, IBS, or a menstrual cycle. Less often, it points to a urinary, kidney, or gynecologic problem that needs prompt attention.

1. Trapped Gas and Swallowed Air

What it is: Gas that builds up in the stomach and intestines from normal digestion or from swallowed air.

Why it happens: Eating too fast, carbonated drinks, chewing gum, and certain high-fiber foods can all lead to gas buildup that stretches the intestine.

Common symptoms: A tight, swollen feeling in the belly, audible rumbling, frequent belching or passing gas, and a dull ache that can radiate to the lower back when the intestine stretches.

Risk factors: Eating quickly, drinking carbonated beverages, lactose intolerance, and beans or cruciferous vegetables.

When to seek evaluation: Occasional bloating and mild back discomfort that ease after passing gas usually do not need urgent care, but frequent or worsening episodes are worth mentioning to a doctor.

2. Constipation

What it is: Infrequent or difficult bowel movements with stool that is hard or hard to pass.

Why it happens: Low fiber or fluid intake, inactivity, certain medications, and ignoring the urge to go can slow movement through the colon, allowing stool and gas to build up.

Common symptoms: Abdominal bloating and fullness, straining, hard or lumpy stool, and a dull, aching lower back pain that often improves after a bowel movement.

Risk factors: A low-fiber diet, dehydration, inactivity, pregnancy, and medications such as opioids or iron supplements.

When to seek evaluation: See a doctor if constipation lasts more than a few weeks, alternates with diarrhea, or comes with blood in the stool or unintended weight loss.

3. Irritable Bowel Syndrome (IBS)

What it is: A common digestive disorder that affects how the intestines move and react, without visible damage on standard tests.

Why it happens: The exact cause is unclear, but it involves how the gut and nervous system communicate, often worsened by certain foods, stress, or hormonal changes.

Common symptoms: Recurring bloating, cramping abdominal pain, and changes in bowel habits such as constipation or diarrhea, with some people also feeling a dull ache in the lower back during flares.

Risk factors: A family history of IBS, high stress levels, and a past gut infection.

When to seek evaluation: Any new or worsening digestive symptoms should be reviewed by a doctor to confirm the diagnosis and rule out other conditions, especially with rectal bleeding or weight loss.

4. Premenstrual Syndrome and Menstrual-Related Back Pain

What it is: Hormonal changes in the days before and during a period that affect digestion and pelvic muscles.

Why it happens: Shifting estrogen and progesterone can slow digestion and cause fluid retention, while prostaglandins that trigger uterine contractions can also affect back muscles and nerves.

Common symptoms: Abdominal bloating, breast tenderness, mood changes, and a dull, cramping lower back pain that typically starts a few days before the period and eases once it ends.

Risk factors: A history of painful periods, high stress, and a family history of premenstrual symptoms.

When to seek evaluation: Talk to a doctor if symptoms are severe enough to disrupt daily life, or if the pattern changes significantly from your usual cycle.

5. Urinary Tract Infection

What it is: A bacterial infection anywhere along the urinary tract, most often the bladder.

Why it happens: Bacteria enter the urinary tract, usually from the bowel, and multiply in the bladder or travel up toward the kidneys.

Common symptoms: Burning when urinating, urinary urgency, cloudy or strong-smelling urine, lower abdominal bloating, and a dull ache in the lower back. Fever and chills suggest the infection has reached a kidney.

Risk factors: Being female, sexual activity, a history of prior UTIs, and pregnancy.

When to seek evaluation: See a doctor promptly for urinary symptoms with back pain, and seek same-day care if fever or shaking chills develop, since an untreated kidney infection can become serious.

6. Persistent, Unexplained Bloating (a Possible Ovarian Cancer Warning Sign)

What it is: In rare cases, ongoing bloating that will not go away is one of the recognized early symptoms of ovarian cancer.

Why it happens: A growing mass or fluid buildup in the pelvis can press on nearby organs and the lower back.

Common symptoms: New bloating most days for more than two weeks, along with lower back or pelvic pain, feeling full quickly when eating, and increased urinary frequency.

Risk factors: Increasing age, a family history of ovarian or breast cancer, and inherited gene changes such as BRCA1 or BRCA2.

When to seek evaluation: See a doctor, ideally a gynecologist, if bloating and back pain persist most days for more than two weeks and are new for you. Earlier evaluation gives more treatment options.

7. Abdominal Aortic Aneurysm

What it is: A bulge in the wall of the body's main artery as it passes through the abdomen, which can leak or rupture.

Why it happens: Wear on the artery wall, often related to atherosclerosis, high blood pressure, and smoking, weakens the vessel over time.

Common symptoms: A deep, steady pain in the abdomen or lower back, sometimes with a pulsing feeling in the belly. A sudden tearing pain can signal a rupture.

Risk factors: Age over 65, a smoking history, high blood pressure, and a family history of aneurysms.

When to seek evaluation: Sudden, severe back or abdominal pain, especially with dizziness or fainting, is a medical emergency and needs a 911 call right away.

When to Seek Medical Care