Constant or recurring stomach pain most often stems from a functional digestive disorder, meaning the gut isn’t working properly even though nothing looks visibly wrong on scans or scopes. Irritable bowel syndrome and functional dyspepsia are the two most common culprits, but the list of possible causes is long, ranging from bacterial infections and inflammation to structural problems like hernias and gallstones. Where you feel the pain, what makes it better or worse, and what other symptoms come with it all help narrow down what’s going on.
Functional Disorders: The Most Common Cause
Functional digestive disorders are responsible for the majority of chronic stomach pain. These conditions cause real, persistent symptoms, but the digestive tract looks normal on imaging and endoscopy. The two big ones are irritable bowel syndrome (IBS) and functional dyspepsia.
IBS affects roughly 1 in 51 people and centers on recurring abdominal pain tied to changes in bowel habits. To qualify as IBS, the pain needs to occur at least one day per week for three months, with symptoms starting at least six months before that. The pain must be linked to at least two of these: going to the bathroom (either relief or worsening), a change in how often you go, or a change in stool consistency. Some people lean toward constipation, others toward diarrhea, and many alternate between both.
Functional dyspepsia is even more prevalent, affecting about 1 in 23 people. It causes pain or burning in the upper stomach area, fullness after eating, or an inability to finish meals. Like IBS, it doesn’t show up on tests. The two conditions can overlap, and stress, poor sleep, and certain foods tend to make both worse.
Infections and Inflammation
A bacterial infection called H. pylori is one of the most treatable causes of ongoing stomach pain. This bacterium damages the protective lining of the stomach and small intestine, allowing stomach acid to create open sores (ulcers) or trigger widespread irritation of the stomach lining (gastritis). The hallmark symptom is an aching or burning pain in the stomach area that feels worse when your stomach is empty. Many people notice it between meals or in the middle of the night. A simple breath test or stool test can detect H. pylori, and a course of antibiotics typically clears it.
Gastritis can also develop without H. pylori. Long-term use of anti-inflammatory painkillers, heavy alcohol use, and autoimmune conditions can all inflame the stomach lining and produce a persistent gnawing or burning sensation in the upper abdomen.
Inflammatory Bowel Disease
Crohn’s disease and ulcerative colitis fall under the umbrella of inflammatory bowel disease (IBD). Unlike IBS, IBD involves visible, destructive inflammation that can be seen on imaging and during colonoscopy. It can cause permanent damage to the intestines and carries an increased risk of colon cancer.
The distinction from IBS matters. IBD typically produces symptoms that IBS does not: blood in the stool, unintended weight loss, anemia, and fever. Crohn’s disease tends to cause progressive pain, often in the lower right abdomen, while ulcerative colitis centers on the large intestine and frequently involves bloody diarrhea. If your stomach pain comes with any of those additional symptoms, that shifts the urgency significantly.
Delayed Stomach Emptying
Gastroparesis is a condition where the stomach takes far too long to move food into the small intestine. It often results from damage to the vagus nerve, which controls stomach muscle contractions. When that nerve can’t send proper signals, food sits in the stomach much longer than it should. The result is upper abdominal pain, nausea, feeling full after just a few bites, and bloating that lingers long after a meal. Diabetes is the most common underlying cause, though in many cases no clear trigger is found.
What the Location of Pain Tells You
The quadrant of your abdomen where pain concentrates can point toward specific organs and conditions.
- Upper right: Gallstones, gallbladder inflammation, liver problems, or kidney stones on that side. Gallstone pain often flares after fatty meals and radiates toward the right shoulder blade.
- Upper left: Gastritis, stomach ulcers, pancreas problems, or, less commonly, heart-related pain. Persistent upper left pain with nausea and back pain can signal pancreatitis.
- Lower right: Appendicitis (usually acute, not chronic), Crohn’s disease, IBS, ovarian cysts, or kidney stones.
- Lower left: Diverticulitis (particularly in adults over 50), IBS, IBD, or gynecologic conditions like ovarian cysts and endometriosis.
Pain that’s hard to pin down to one spot, or that moves around, is more typical of functional disorders like IBS or dyspepsia. Conditions involving a specific organ tend to produce pain that’s more localized and predictable.
Other Conditions Worth Knowing
Several other conditions commonly cause persistent abdominal pain. Celiac disease, an immune reaction to gluten, damages the small intestine and produces bloating, pain, diarrhea, and fatigue. Endometriosis can cause cyclical or constant lower abdominal pain when tissue similar to the uterine lining grows outside the uterus. Gastroesophageal reflux disease (GERD) causes a burning sensation in the upper stomach and chest when acid repeatedly flows back into the esophagus. Hiatal hernias, where part of the stomach pushes through the diaphragm, can produce similar symptoms.
Ovarian cysts cause pain that’s typically one-sided and may come and go with the menstrual cycle. Pelvic inflammatory disease, an infection of the reproductive organs, produces lower abdominal pain often accompanied by unusual discharge or fever.
How Persistent Stomach Pain Gets Diagnosed
Because the list of possible causes is so long, diagnosis usually follows a step-by-step process. The first round typically includes blood work looking at blood cell counts, liver and kidney function, and markers of inflammation. Depending on your symptoms, your doctor may also order a celiac screen, a thyroid check, or a test for H. pylori through a breath test or stool sample. An abdominal ultrasound is commonly done early on to rule out gallstones, kidney stones, ovarian cysts, and other structural problems.
If those initial tests come back normal but symptoms persist, a CT scan of the abdomen and pelvis may be the next step. Endoscopy (a camera down the throat to examine the stomach) or colonoscopy may follow, particularly if there are alarm features. It’s worth noting that when these scopes come back normal, repeating them rarely adds new information. A normal scope is actually reassuring, even if it doesn’t immediately explain your pain, because it means serious structural disease has been ruled out.
Warning Signs That Need Urgent Attention
Most chronic stomach pain is not dangerous, but certain symptoms alongside it signal something more serious. These red flags warrant prompt medical evaluation:
- Unintended weight loss of more than 5% of your body weight over 6 to 12 months
- Visible blood in your stool or black, tarry stools
- Iron deficiency anemia (unexplained fatigue, pallor, shortness of breath)
- Persistent vomiting, especially if you can’t keep liquids down
- New onset of symptoms after age 50
- Family history of inflammatory bowel disease or colorectal cancer
- Fever alongside abdominal pain
Pain so severe it interrupts your ability to function, or pain that feels distinctly different from a pattern you’ve had before, also justifies an emergency visit. The same goes for abdominal pain after a recent surgery, or constipation with severe pain and an inability to pass gas.