Pain in the lower left part of your stomach most commonly comes from your digestive system, specifically the sigmoid colon, which is the S-shaped section of your large intestine that sits in that exact area. The cause can range from something as harmless as trapped gas to conditions that need prompt medical attention, like diverticulitis or an ovarian cyst. What matters most is how the pain feels, how long it lasts, and what other symptoms come with it.
What’s Actually in That Area
The lower left quadrant of your abdomen houses the end of your large intestine: the descending colon running down your left side and the sigmoid colon curving toward your rectum. Parts of your small intestine sit there too. If you’re female, your left ovary and fallopian tube are also in this region. A left-sided kidney stone can send pain radiating down into this area as well, even though the kidney itself sits higher up. So the pain could be intestinal, reproductive, or urinary in origin.
Gas and Constipation: The Most Likely Culprit
Trapped gas is probably the single most common reason for temporary lower left abdominal pain. The sigmoid colon has a sharp curve where gas can get stuck, creating pressure, bloating, and crampy discomfort that shifts around. Constipation works the same way: stool backs up in the sigmoid colon and stretches the intestinal wall, producing a dull ache or intermittent cramping.
The key feature of gas or constipation pain is that it comes and goes, often improves after passing gas or having a bowel movement, and doesn’t come with fever or worsening symptoms over hours. If the pain resolves within a day or so on its own, it was likely nothing serious.
Diverticulitis: The Condition Most Linked to This Location
Diverticulitis is the condition doctors think of first when someone reports persistent lower left abdominal pain with fever. It happens when small pouches that form in the colon wall (diverticula) become inflamed or infected. About 70% of people with acute diverticulitis report left lower abdominal pain as their main symptom.
The pain is typically sharp and distinct, not vague or gassy. It often builds over several hours and stays in one spot rather than moving around. Fever is common. You may also notice nausea, bloating, constipation, or a loss of appetite. Some people have trouble passing gas or stool at all.
Diverticular disease has become more common over the past two decades, and it’s increasingly showing up in people younger than 50. Your risk goes up with age, a low-fiber diet, constipation, and high meat intake. Mild cases can sometimes resolve within a day or two with rest and a liquid diet. More significant flares typically require a course of antibiotics lasting 7 to 10 days. A CT scan is the standard way doctors confirm the diagnosis, with sensitivity as high as 98%.
How to Tell It Apart From Gas
Gas pain tends to be diffuse, crampy, and relieved by passing gas. Diverticulitis pain is sharper, stays put, and gets worse over hours rather than better. If you develop fever, your pain keeps escalating, you see blood in your stool, or you’re bloated and vomiting, those signs point away from simple gas and toward something that needs medical evaluation.
Gynecological Causes in Women
If you have a left ovary, several conditions can produce pain in exactly this spot.
Ovarian cysts are one of the most common causes of sudden pelvic pain in younger women. Functional cysts, the kind that form during normal ovulation, can bleed or rupture. A ruptured cyst typically causes a sudden, sharp pain on one side that may come with lightheadedness if there’s significant internal bleeding. Most resolve on their own, but severe cases with heavy bleeding can cause dangerously low blood pressure.
Ectopic pregnancy, where a fertilized egg implants outside the uterus (usually in a fallopian tube), is a potentially life-threatening emergency. It’s the leading cause of maternal death in the first trimester. Rupture often occurs between 10 and 14 weeks and causes severe abdominal pain, vaginal bleeding, and sometimes shock. If there’s any chance you could be pregnant and you’re having one-sided lower abdominal pain, this needs to be ruled out quickly. Ultrasound is the preferred first imaging test for women of childbearing age with this type of pain.
Endometriosis, where tissue similar to the uterine lining grows outside the uterus, more commonly causes chronic, cyclical pelvic pain. But it can also flare acutely if an endometrioma (a blood-filled cyst on the ovary) ruptures or if endometrial implants cause bowel obstruction.
Kidney Stones
A stone moving through your left ureter, the tube connecting your kidney to your bladder, can produce pain that starts in your side and back below the ribs and radiates down into the lower abdomen and groin. This pain is often described as the worst pain someone has ever felt. It comes in waves, and you may feel restless and unable to find a comfortable position, which is different from the stillness people prefer with abdominal inflammation.
Hernias
An inguinal hernia on the left side can cause pain, pressure, or a burning sensation in your lower abdomen near the pubic bone. The hallmark is a visible or palpable bulge that becomes more obvious when you stand up, cough, or strain. Pain tends to worsen with bending, lifting, or coughing. In men, the protruding tissue can descend into the scrotum, causing swelling and discomfort there as well.
Most inguinal hernias aren’t emergencies, but a strangulated hernia, where the blood supply to the trapped tissue gets cut off, is. Signs include sudden worsening pain, nausea and vomiting, fever, and a bulge that turns red or purple. That situation requires surgery.
Signs That Need Urgent Attention
Certain combinations of symptoms suggest something serious is happening. Seek prompt medical care if you have:
- Severe pain that came on suddenly and keeps getting worse over hours
- Fever with abdominal pain, which suggests infection or inflammation
- Blood in your stool or vomit, or dark, tarry stools
- Abdominal bloating with vomiting and inability to pass gas or stool, which can signal a bowel obstruction
- Pain that worsens with any movement, like bumping into something or hitting a bump in the car, which is a classic sign of peritonitis (inflammation of the abdominal lining)
How Doctors Figure Out the Cause
For most people with lower left abdominal pain, the diagnostic process starts with a physical exam, your symptom history, and sometimes blood work to check for signs of infection or inflammation. If the picture points toward diverticulitis or another serious cause, a CT scan of the abdomen and pelvis is the gold standard. It can confirm diverticulitis, identify complications like abscesses or perforations, and also catch other conditions that mimic diverticulitis.
For women of childbearing age, doctors typically start with a pelvic ultrasound instead, which is better suited to evaluating ovarian cysts, ectopic pregnancy, and other reproductive causes. In some cases, both ultrasound and CT end up being needed to get the full picture.
The bottom line: brief, crampy pain that comes and goes and resolves within a day is usually gas or constipation. Pain that persists, intensifies, or arrives with fever, bleeding, or vomiting tells a different story and warrants a closer look.