And the last thing you want is surgery on the fly. So take the first steps in protecting yourself: Track the exact location and duration of the pain, and any changes you notice, says David Rubin, MD, chief of gastroenterology, hepatology, and nutrition at the University of Chicago Medicine. Finding the correct diagnosis means communicating these things clearly to your doctor. A few more disclaimers before the main event: Talk to your doctor immediately if you’re losing weight rapidly, waking up in pain, or see blood in your stool. And remember that just as intestinal issues may manifest in the joints, shoulder, or chest (think acid reflux), abdominal pain may actually be a result of a heart issue or a gynecological one. Assuming the problem does start in your gut, here’s your guide to five common causes of persistent stomach pain:    GallstonesThe target demographic: Female, over 40, had children. Why? The estrogen spike in pregnancy may cause gallstones, which float around undetected for years. “Once they’re there, they’re there,” says David Hudesman, MD, director of inflammatory bowel disease at NYU Langone Medical Center. “The question is, when will they need to be treated?” Look for dull pain near the right shoulder coupled with discomfort around the belly button as an early sign of inflammation. Also, get checked if greasy or spicy food consistently triggers abdominal pain, or discomfort wakes you in the middle of the night. MORE: 15 Awkward Questions You Only Ask Dr. Google   Helicobacter PyloriHelicobacter Pylori, a bacterium that’s lived in humans for the last 58,000 years, is notoriously cruel to people over 40. Scientists think it evolved to help us regulate weight and boost immunity in youth, and then usher us off life’s stage once our childbearing years have passed (yeesh). We all have some H. Pylori in our systems, but if the population gets out of control it can wreak havoc. It often starts with discomfort in the upper abdomen, such as bloating and a distended belly, and leads to ulcers or, worst case, gastric cancer. If you have that pregnant feeling, but know you’re not, ask your doctor to check for H. Pylori. “The blood test is simple and effective,” says Diane Abraczinskas, MD, of the Mass General Hospital Digestive Healthcare Center. “If the bacterium is present, you’ll eradicate it early.”   Inflammatory Bowel DiseaseBusy doctors often miss the slow onset of the inflammatory bowel diseases Crohn’s, and ulcerative colitis, which is why Rubin insists patients track symptoms and ask for the right tests. Severe cramps that last for more than 12 hours, waking in the night, and blood in the stool are all warning signs of ulcers in the GI tract. If you have joint pain, red eyes, sores in the mouth, plus abdominal cramping, those could indicate Crohn’s. And, in general, don’t take ibuprofen regularly for joint pain, says Rubin. Habitual use of it is bad news for the intestinal wall, which leads to ulcers and exacerbates IBD.   Lactose IntoleranceGetting gassy from Greek yogurt like never before? Turns out lactose intolerance often appears out of the blue in adulthood. “Patients who always ate dairy will suddenly not tolerate it and not understand why,” says Abraczinskas. Interestingly, a common type of food poisoning called norovirus can be the culprit that causes it. Norovirus passes through and sometimes kills the enzyme that breaks down lactose. Most people take about two years to recover, but some unfortunate souls never do.  MORE: Calcium Sources For The Lactose Intolerant   Irritable Bowel Syndrome (IBS)Embarrassing symptoms—gas, bloating, diarrhea—that last 12 weeks or more might be irritable bowel syndrome (learn more about the specific symptoms of IBS here). Uncomfortable? Very. But don’t despair. Improvements in diet, exercise, stress levels, and gut flora may relieve its symptoms, says Hudesman. Also, IBS shouldn’t wake you from sleep nor should it suddenly appear if you’re over 60. If that happens, something else is going on. MORE: 7 Simple Steps To A Super Gut