Pain at the bottom of your stomach, what doctors call the lower abdomen, usually comes from the intestines, bladder, or reproductive organs rather than the stomach itself. The cause can range from something as simple as trapped gas to conditions that need prompt treatment, and where exactly you feel the pain, along with what other symptoms you notice, narrows down the possibilities significantly.
What’s Actually Down There
Your lower abdomen sits below your belly button and above your pelvis. The right side houses your appendix, the beginning of your large intestine, and your right ureter (the tube connecting your kidney to your bladder). The left side contains the end of your large intestine, including the sigmoid colon, and the left ureter. The bladder sits right in the center, low and behind the pubic bone. In women, the ovaries and fallopian tubes sit on both sides, and the uterus is in the middle.
Which side hurts matters. Pain on the right can point to your appendix. Pain on the left often involves the lower colon. Pain in the center may involve the bladder or, in women, the uterus. And pain that’s hard to pin down to one spot is more typical of gas, constipation, or a stomach bug working its way through your intestines.
Gas and Constipation: The Most Common Culprits
The simplest explanation is often the right one. Trapped gas and backed-up stool are by far the most frequent reasons for lower abdominal pain, and they can hurt more than you’d expect. When excess gas gets stuck in your gut, the feeling ranges from mild discomfort to sharp, cramping pain. Your belly may feel tight and distended, like an overinflated balloon.
Constipation makes things worse because stool and gas get trapped together. A digestive system that’s moving slowly creates more opportunity for gas to build up. The pain tends to come in waves or cramps, often eases after passing gas or having a bowel movement, and doesn’t come with fever or vomiting. If you’ve been eating differently, traveling, stressed, or dehydrated, this is the most likely explanation. Increasing water, fiber, and movement usually resolves it within a day or two.
Appendicitis: Right Side Pain That Gets Worse
Appendicitis is the condition most people worry about with lower right pain, and it’s worth knowing the pattern. The classic progression starts with a vague ache around your belly button that migrates over several hours to the lower right side. The specific spot where it settles is roughly a third of the way along an imaginary line drawn from your belly button to the bony point of your right hip.
The pain typically gets steadily worse rather than coming and going. Walking, coughing, or pressing on the area and then releasing makes it spike. Other signs include loss of appetite, nausea or vomiting, fever, an inability to pass gas, and constipation or diarrhea. If this pattern matches what you’re feeling, especially if the pain started around your belly button and moved, don’t wait to see if it resolves on its own.
Diverticulitis: Left Side Pain, Usually Over 50
Diverticulitis is a leading cause of sudden lower left abdominal pain, particularly in adults over 50. Small pouches called diverticula form in the walls of the colon over time and are extremely common with age. When one of these pouches becomes inflamed or infected, the result is a sharp, often intense pain in the lower left abdomen.
The pain can come on suddenly or start mild and worsen over a few days, sometimes varying in intensity. It’s usually accompanied by tenderness when you press the area, changes in bowel habits (sudden constipation or diarrhea), nausea, and sometimes fever. Mild cases are treated with rest and a temporary change in diet. More severe episodes, especially those with high fever or worsening pain, need medical evaluation because complications like abscesses or perforations can develop.
Bladder and Urinary Tract Infections
A bladder infection causes pain or pressure low in the center of your abdomen, right behind your pubic bone. The giveaway is that urinary symptoms come along with it: burning when you pee, a constant urge to go even when your bladder is nearly empty, cloudy or strong-smelling urine, and sometimes blood in your urine. The lower abdominal discomfort tends to feel like a dull ache or heaviness rather than a sharp pain. Women get bladder infections far more often than men, but they can happen to anyone.
Causes Specific to Women
The reproductive organs add several possibilities for lower abdominal pain in women. Menstrual cramps are the most obvious, but when pain is unusually severe or occurs outside your period, other conditions come into play.
Endometriosis happens when tissue similar to the uterine lining grows outside the uterus, most commonly on the ovaries, fallopian tubes, and tissue lining the pelvis. The hallmark symptom is pelvic pain that goes beyond normal menstrual cramping. It can include lower back and abdominal pain, pain during sex, pain with bowel movements, and fatigue, bloating, or nausea around your period. The severity of pain doesn’t always match the extent of the condition. Some people with a small amount of tissue have severe pain, while others with widespread tissue have little discomfort at all.
Ovarian cysts can cause a dull ache or sudden sharp pain on one side of the lower abdomen, especially if a cyst ruptures or twists. Pelvic inflammatory disease, an infection of the reproductive organs usually caused by sexually transmitted bacteria, produces lower abdominal pain along with unusual discharge, fever, and pain during sex. Both conditions can mimic each other and are worth evaluating if lower abdominal pain persists or recurs.
Causes More Common in Men
Inguinal hernias are a frequent source of lower abdominal and groin pain in men. They occur when tissue, usually part of the intestine, pushes through a weak spot in the abdominal wall near the groin. The telltale sign is a visible bulge in the groin or scrotum that may come and go. You’ll notice discomfort, heaviness, or a burning sensation in the area, and symptoms tend to get worse when you strain, lift, cough, or stand for a long time. Lying down usually brings relief.
Most hernias aren’t emergencies, but they can become one. If a hernia bulge suddenly gets larger, turns red, becomes very painful, or won’t push back in anymore, the trapped tissue may be losing its blood supply. That situation, called a strangulated hernia, causes severe pain, nausea, vomiting, and fever, and needs immediate treatment.
Signs That Need Urgent Attention
Most lower abdominal pain resolves on its own or with simple measures. But certain patterns signal something that shouldn’t wait. Go to an emergency room if your pain is severe and constant, if you’re vomiting and can’t keep liquids down, if you have a fever along with the pain, if your abdomen is swollen and rigid, or if you’re unable to pass gas or have a bowel movement while in significant pain. Pain that resembles something you’ve experienced before but feels more severe or different this time also warrants evaluation.
How Lower Abdominal Pain Gets Diagnosed
If you see a doctor for lower abdominal pain, expect questions about exactly where it hurts, when it started, what makes it better or worse, and what other symptoms you have. A physical exam, including pressing on different areas of your abdomen, helps narrow the possibilities. Beyond that, the most common imaging tool for lower abdominal pain on either side is a CT scan, which gives a detailed view of the intestines, appendix, and surrounding structures. For pregnant patients, ultrasound or MRI is used instead to avoid radiation. Blood tests and urine tests help identify infection or inflammation.
The specific location and your other symptoms usually point the diagnosis in one direction fairly quickly. Pain that’s been building for hours with fever and tenderness gets worked up fast. Crampy, on-and-off discomfort without other red flags is more likely to be evaluated over days rather than hours, starting with dietary changes and monitoring before moving to imaging.