Pain below your stomach, in the lower part of your abdomen, usually comes from your intestines, bladder, or reproductive organs rather than your stomach itself. The cause depends on exactly where it hurts, how the pain started, and what other symptoms you’re experiencing. Most cases turn out to be something manageable like gas, constipation, or a mild infection, but certain patterns of lower abdominal pain signal problems that need prompt attention.
What’s Actually Down There
Your stomach sits higher than most people think, tucked up behind your lower ribs. The area below it, from your belly button down to your pelvis, contains a different set of organs entirely. On the right side, you’ll find your appendix, part of your small intestine, and the beginning of your large intestine (the cecum and ascending colon). On the left side sits the end of your large intestine, the descending and sigmoid colon, and more small intestine. In the center, behind your pubic bone, your bladder sits low in the pelvis. For women, the uterus, fallopian tubes, and ovaries occupy the middle and lower sides. For men, the prostate gland sits just below the bladder.
Pain in any of these areas can feel like it’s “below the stomach,” but pinpointing which side hurts, and whether the pain is sharp, crampy, or dull, helps narrow down the source.
Digestive Causes
The most common reasons for lower abdominal pain are digestive. Constipation and trapped gas can create surprisingly intense cramping, especially on the left side where stool collects before a bowel movement. This kind of pain usually comes and goes in waves and improves after passing gas or having a bowel movement.
Irritable bowel syndrome (IBS) causes recurring lower abdominal pain along with changes in bowel habits, either diarrhea, constipation, or both. The key feature of IBS is that symptoms are chronic, lasting weeks or months rather than days. Pain tends to center in the lower abdomen with tenderness you can feel when pressing on the area. Because IBS symptoms overlap heavily with other conditions, doctors look at how long you’ve had the problem. Chronicity is one of the most helpful clues in distinguishing IBS from other lower abdominal issues.
Diverticulitis, an inflammation of small pouches that form in the colon wall, typically hits the lower left side. It can cause steady pain, tenderness, and sometimes fever, though some people with confirmed diverticulitis have no fever at all. It’s more common after age 40 and often follows a low-fiber diet over many years.
Bladder and Urinary Tract Problems
A bladder infection (cystitis) creates a distinctive pressure or discomfort right behind your pubic bone, in the lowest center of your abdomen. You’ll usually notice other telltale signs: a persistent urge to urinate, burning during urination, passing only small amounts frequently, and urine that looks cloudy or smells strong. Some people develop a low-grade fever. Blood in the urine can occur but is less common with a typical bacterial infection.
Kidney stones produce a different kind of pain. It typically starts in your flank (the side of your back, below the ribs) and migrates downward as the stone moves through the urinary tract. The pain is severe and colicky, meaning it surges and fades in waves rather than staying constant. In men, stone pain can radiate into the testicles.
Reproductive Causes in Women
Menstrual cramps are the most obvious cyclical cause of lower abdominal pain, but two conditions deserve attention when the pain is more severe or persistent.
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus, usually on pelvic surfaces. These implants bleed along with the menstrual cycle, causing pain and scarring. The hallmark is pelvic pain that worsens around your period but can also occur between periods or during sex. Roughly 10% of women of reproductive age are affected, and chronic pelvic pain is the most common reason they end up seeing a gynecologist.
Ovarian cysts form as a normal part of the menstrual cycle and usually resolve on their own. Many rupture without you even noticing. But a larger cyst can cause a dull ache on one side of the lower abdomen, and a rupture sometimes produces sudden, sharp pain. If a cyst twists the ovary (ovarian torsion), the pain is severe and requires emergency treatment. An ectopic pregnancy, where a fertilized egg implants in a fallopian tube instead of the uterus, may start as a dull pain that worsens into sharp, stabbing pain. If the tube ruptures, excruciating pain spreads throughout the abdomen. This is a medical emergency.
Reproductive Causes in Men
Prostatitis, or inflammation of the prostate, causes pain in the lower belly, groin, or the area between the scrotum and rectum. It can also cause painful ejaculation and discomfort in the penis or testicles. The chronic form, called chronic pelvic pain syndrome, produces symptoms that come and go over months. It’s frustratingly common in younger men and often doesn’t involve a bacterial infection, which means antibiotics don’t always help.
Hernias
An inguinal hernia occurs when tissue, often part of the intestine, pushes through a weak spot in the abdominal wall near the groin. The most obvious sign is a bulge on either side of the pubic bone that becomes more noticeable when you stand up, cough, or strain. You may feel a burning or aching sensation at the bulge, along with pressure in the groin when bending or lifting. In men, the protruding tissue can descend into the scrotum, causing pain and swelling around the testicles.
Most hernias aren’t dangerous at first, but they can become trapped (incarcerated) in the abdominal wall. A strangulated hernia, where blood supply gets cut off, causes sudden worsening pain, nausea, vomiting, fever, and a bulge that turns red or purple. That situation requires emergency surgery.
Appendicitis: The Pain Pattern to Know
Appendicitis follows a recognizable sequence. Pain usually starts as a vague ache around the belly button, then migrates to the lower right abdomen over the course of 12 to 24 hours, becoming progressively more severe. The pain worsens when you move, cough, sneeze, or take deep breaths. Other symptoms include loss of appetite, nausea or vomiting, fever, and an inability to pass gas.
This migration pattern, from the center to the lower right, is the classic warning sign. Not everyone follows the textbook presentation, and the exact location can vary depending on where your appendix sits, but pain that starts suddenly near the belly button and gets worse over hours should be evaluated quickly.
Signs That Need Emergency Attention
Lower abdominal pain that comes with any of the following warrants an ER visit: vomiting you can’t control or an inability to keep liquids down, severe constipation with intense pain, pain that started moderately and has gotten significantly worse over hours, or pain that feels similar to a previous episode but is more severe or different this time. If you’ve had abdominal surgery in the past, new pain in the same area also justifies an emergency evaluation, since adhesions and complications from prior procedures can cause bowel obstructions.
For women of reproductive age, sudden one-sided lower abdominal pain with dizziness, fainting, or shoulder pain could indicate a ruptured ectopic pregnancy or ovarian torsion. Both require immediate care.
How Doctors Figure Out the Cause
Your doctor will start with your history and a physical exam, pressing on different areas of your abdomen to locate tenderness. From there, imaging depends on where the pain is and what’s suspected. For lower right or lower left pain, a CT scan is typically the first imaging choice because it’s the best tool for spotting appendicitis, diverticulitis, and other structural problems. For women of reproductive age, especially if a gynecologic cause or pregnancy is possible, an ultrasound of the pelvis is usually done first. Pregnant women are evaluated with ultrasound or MRI to avoid radiation exposure.
If you’re experiencing ongoing lower abdominal pain that you’ve been managing on your own for weeks, keep track of when it happens, what makes it better or worse, and whether it relates to eating, bowel movements, or your menstrual cycle. That pattern is often the single most useful piece of information for getting to the right diagnosis.