Abdominal pain can be caused by a wide variety of conditions involving different organs and systems in the abdomen. Common causes include:

• Digestive problems such as constipation, indigestion, irritable bowel syndrome (IBS), food allergies or intolerance (e.g., lactose intolerance), food poisoning, and stomach flu.
• Inflammation and infections including appendicitis, cholecystitis (gallbladder inflammation), diverticulitis (colon inflammation), pancreatitis, pelvic inflammatory disease (PID), urinary tract infections, and gastroenteritis.
• Mechanical or structural issues such as bowel blockage or obstruction, hernias, kidney stones, ruptured ovarian cysts, and abdominal aortic aneurysm.
• Chronic diseases such as inflammatory bowel disease (Crohn’s disease, ulcerative colitis), endometriosis, and peptic ulcers.
• Conditions related to female reproductive organs such as severe menstrual cramps, tubal (ectopic) pregnancy, and ovarian cysts.
• Other causes including heartburn, gastroesophageal reflux disease (GERD), muscle strain, and cancers of abdominal organs like stomach or colon cancer.

The nature, location, and duration of the pain, as well as accompanying symptoms (e.g., fever, nausea, vomiting, changes in bowel movements), can help indicate the cause and the urgency of medical attention needed. Some causes are minor and temporary, while others may require immediate medical care.