Pain in the lower left abdomen most commonly comes from the sigmoid colon, the S-shaped segment of your large intestine that sits in that area. In women, the left ovary and fallopian tube are also located there. Depending on the cause, the pain can feel like anything from a dull ache to a sharp, stabbing sensation, and the underlying reasons range from mild constipation to conditions that need urgent care.
What’s Located in the Lower Left Abdomen
The lower left quadrant contains fewer organs than other parts of your abdomen, which actually helps narrow down the possibilities. The sigmoid colon is the main resident, making digestive issues the most frequent explanation for pain in this area. Women also have a left ovary and fallopian tube here, which opens up a second category of causes. The left ureter, which carries urine from the kidney to the bladder, also runs through this region, and the abdominal wall muscles and nerves that cover everything can be a source of pain on their own.
Diverticulitis: The Most Common Serious Cause
Diverticulitis is the condition most closely associated with lower left abdominal pain. It happens when small pouches that form in the colon wall (diverticula) become inflamed or infected. Left lower abdominal pain is the main symptom in about 70% of patients, and the pain is typically crampy. It often comes with a change in bowel habits, either constipation or diarrhea.
Other symptoms that point toward diverticulitis include fever, nausea, vomiting, bloating, and gas. Most cases are uncomplicated, meaning the inflammation hasn’t led to a perforation or abscess. Current guidelines from the UK’s National Institute for Health and Care Excellence recommend that uncomplicated diverticulitis in otherwise healthy people can be managed without antibiotics, since evidence shows they don’t significantly improve recovery time or reduce complications. Antibiotics are reserved for people who are systemically unwell, immunocompromised, or have complicated disease with abscesses or perforations.
Complicated diverticulitis is a different situation. Signs include severe tenderness across the abdomen, a palpable mass, high fever, and inability to pass gas. In rare cases, inflamed diverticula can create a connection (fistula) between the colon and the bladder, which causes air or stool particles to appear in urine.
IBS and Other Bowel-Related Causes
Irritable bowel syndrome is one of the most common reasons for recurring lower left pain. IBS is a functional disorder, meaning the intestines look structurally normal but don’t work the way they should. The muscles lining the intestines can spasm, producing crampy pain. Stronger, longer contractions cause gas, bloating, and diarrhea, while weak contractions slow food down and lead to hard, dry stools.
People with IBS also have oversensitive nerve endings in the digestive tract. Small bubbles of gas that wouldn’t bother most people can be genuinely painful. The brain-gut connection plays a role too: poorly coordinated signals between the brain and intestines cause the body to overreact to normal digestive processes, amplifying discomfort.
Beyond IBS, simple constipation is a frequent culprit. Stool tends to accumulate in the sigmoid colon before a bowel movement, so backup in this area creates pressure and cramping on the left side. Inflammatory bowel diseases like ulcerative colitis, which typically starts in the rectum and sigmoid colon, can also produce left-sided pain along with bloody diarrhea and urgency.
Gynecological Causes in Women
Because the left ovary sits in the lower left quadrant, ovarian cysts are a common source of pain in this area. Most ovarian cysts are small and resolve on their own, causing only mild, dull discomfort. Larger cysts can rupture, producing a sudden, sharp pain that may come with light vaginal bleeding.
Ovarian torsion is a more urgent concern. This happens when the ovary twists on the ligament that holds it in place, cutting off its blood supply. Up to 85% of people diagnosed with ovarian torsion have ovarian cysts or other benign masses that add extra weight to the ovary, making it more likely to shift. The hallmark symptom is sudden, severe lower abdominal pain, often with nausea and vomiting. The pain tends to be sharp and stabbing, though it can also feel dull and crampy. If the tissue starts to die from lack of blood flow, fever and abnormal vaginal discharge or bleeding may follow. Ovarian torsion requires emergency surgery.
Ectopic pregnancy, where a fertilized egg implants outside the uterus (usually in a fallopian tube), can also cause intense one-sided lower abdominal pain. This is a medical emergency, and it’s standard practice to rule it out in any woman of childbearing age who presents with lower abdominal pain.
Kidney Stones and Urinary Causes
A kidney stone moving through the left ureter can produce pain that starts in the flank and radiates down into the lower left abdomen and groin. The pain is often described as coming in waves, with intense peaks that ease off before returning. In men, the pain may radiate to the left testicle because the ureter and the testicle share the same spinal nerve pathways. A small stone lodged in the lower ureter can sometimes cause pain felt mainly in the scrotum, with little or no flank pain, which can make diagnosis tricky.
Hernias and Abdominal Wall Pain
Not all lower left pain comes from internal organs. Hernias and muscle strains in the abdominal wall can mimic organ pain convincingly. An inguinal hernia on the left side may compress the ilioinguinal nerve even before there’s a visible bulge, producing neuropathic pain that worsens with coughing, straining, or pressing on a specific spot. The pain can come and go: if the hernia spontaneously reduces (slips back inside), the bloating, cramping, nausea, and pain resolve completely, and there are no physical signs of anything wrong.
In women, less common hernias (obturator, sciatic, or perineal) can present as chronic pelvic pain that mimics conditions like endometriosis or interstitial cystitis. These patients sometimes go through multiple treatments for other diagnoses before the hernia is identified as the actual source.
How Doctors Figure Out the Cause
A CT scan of the abdomen and pelvis with contrast is the preferred first-line imaging test for lower left abdominal pain. It’s the most useful tool regardless of your sex or body type, with a diagnostic accuracy of 98% for diverticulitis specifically. CT can also detect free air in the abdomen (a sign of perforation), abscesses, fistulas, and a range of alternative diagnoses that present similarly.
Ultrasound plays a more limited role. It’s not widely used in the U.S. for non-gynecological lower left pain, though some European countries use it as a first step for suspected diverticulitis. The main drawback is accuracy: studies show ultrasound may miss up to 80% of complicated diverticulitis cases. For gynecological causes like ovarian cysts or torsion, however, ultrasound is a standard and effective tool. Blood work typically checks for elevated white blood cells and inflammatory markers, and a urine test can help identify kidney stones or, in unusual cases, a fistula between the colon and bladder.
Warning Signs That Need Urgent Attention
Most lower left abdominal pain turns out to be something manageable, but certain symptoms signal a more serious problem. These include:
- Severe pain that comes on suddenly or keeps getting worse
- Fever or chills
- Vomiting blood or blood in your stool or urine
- Inability to pass gas or have a bowel movement
- Shortness of breath
- Yellowing of the skin or eyes
- Pain that keeps returning or mild pain that has gradually worsened over time
Any of these combinations warrants a call to your doctor or a visit to the emergency room, particularly sudden severe pain with nausea and fever, which could indicate anything from a perforated diverticulum to ovarian torsion to a bowel obstruction.