When your belly hurts

Several years ago, I received two middle-of-the-night phone calls within minutes of each other. Both calls were from men in their 40s. Each complained of abdominal pain, nausea, and vomiting, and each had undergone an appendectomy. There the similarities ended. The first caller also had diarrhea and a low-grade fever. The second caller didn't. Which one was sicker?

You might think the one with more symptoms was in worse shape. But he was suffering from gastroenteritis, probably caused by a virus, and was feeling better the next morning. The other fellow turned out to have an intestinal obstruction caused by scar tissue from his appendix operation. He had to have emergency surgery.

Sudden onset of abdominal pain can be frightening for patients and a challenge for doctors. When pain is limited to one part of the belly, the diagnosis is easier but the cause might be more serious. Pain in the patient's right-upper abdomen can indicate gallstones or inflammation; in the mid-upper abdomen, stomach or pancreas problems; in the right-lower abdomen, an inflamed appendix; and in the left-lower abdomen, diverticulitis.

Problems of the small intestine, such as those experienced by my two patients, usually cause allover abdominal pain. Kidney pain typically begins in the back and can radiate to the abdomen.

In women the ovaries can cause pain by twisting or by forming cysts that occasionally rupture. Pregnancy adds even more possibilities.

Pinpointing the cause of abdominal pain would be relatively easy if nature were simple. But it's not. A leaking aortic aneurysm, a tear in the wall of the body's largest blood vessel, often produces abdominal pain and can be fatal if it's not tended to immediately.

An inflamed appendix can "hide" behind the colon and cause pain in the upper abdomen. Bowel obstruction can develop when a small segment of bowel becomes trapped in an undetected hernia.

The most common causes of abdominal pain are generally the least serious, even though they can be temporarily disabling. Upper-abdominal pain is often due to simple gastritis, or stomach inflammation. A common cause is the overuse of aspirin or another anti-inflammatory medication (ibuprofen, naproxen). If that's the case, stop the medication and take an over-the-counter antacid for a few days, and the discomfort should subside.

Gastroenteritis, caused by a virus, is a frequent cause of allover abdominal pain and is usually accompanied by nausea, vomiting, diarrhea, and mild fever; it subsides on its own in a few days. The most common kind of food poisoning usually has similar symptoms, minus the fever, and is over in a day or so. If the symptoms are tolerable, you can probably manage by staying well-hydrated and taking the pain reliever acetaminophen for discomfort. If uncertain, seek medical attention.

Any abdominal pain that lasts more than a few hours is a potential problem.

Seek medical attention if the pain is severe, located in a specific area, or accompanied by:

• Weakness, dizziness, or sweating, signs of possible intestinal bleeding or a ruptured aneurysm.
• The passage of bloody or tar-like stools.
• Nausea and vomiting, with diarrhea (infection) or without (blockage).
• Pregnancy.
• Shaking, chills, and fever, signs of infection.
• A bulge in the groin, possibly a hernia.
• Blood in the urine, a sign of a kidney stone or a urinary-tract infection.