A stomachache, otherwise known as abdominal pain, could come from any of a number of causes. It can indicate conditions of varying severity, ranging from lactose intolerance to peptic ulcers to emergency appendicitis.

Emergency medicine doctors use diagnostic tools and physical exams to determine why a patient is experiencing discomfort, uncover the source of the pain, and rule out more serious conditions. While not all abdominal pain is cause for worry, Yale Medicine emergency department doctors treat every patient with care and attention to make sure that the root problem is addressed as quickly as possible.

The most common causes of abdominal pain are related to the gastrointestinal tract. These include:

• Gastroesophageal reflux, heartburn or acid stomach caused by the return of the stomach's contents back up into the esophagus
• Peptic ulcer disease, which refers to sores in the lining of the stomach or the first part of the small intestine, called the duodenum
• Gastritis, inflammation of the lining of the stomach
• Bowel obstruction, blockage of the small or large intestine

Abdominal pain can also be caused by inflammation in other parts of the body, including:

• Pancreatitis, inflammation of the pancreas
• Hepatitis, inflammation of the liver
• Colitis, inflammation of the bowel
• Perticulitis, inflammation of the perticulum

When a female patient comes into the emergency department with abdominal pain, doctors will almost always order a pregnancy test to rule out ectopic pregnancy, a life-threatening condition that occurs when the fertilized egg implants in a place other than the uterus.

Pelvic inflammatory disease and endometriosis are other common causes of abdominal pain in women.

“The most common cause of abdominal emergency in young people is appendicitis,” says Yale Medicine emergency physician Vivek Parwani, MD, assistant professor of emergency medicine at the Yale School of Medicine and medical director at Yale New Haven Hospital’s Adult Emergency Department. “In those older than 55, the most common cause is actually gall bladder disease.”

While pain from peptic ulcers is not often cause for emergency intervention, a torn or perforated ulcer can be life-threatening.

Women experiencing severe abdominal pain and vomiting may have twisted ovaries or ovarian torsion. Doctors will examine men for twisted testicles or torsion. Both conditions are extremely painful and require emergency treatment.

Doctors also assess patients to rule out mesenteric ischemia, a dangerous vascular blockage, and abdominal aneurysms.

Constipation is one of the most common causes of abdominal pain in children, says Dr. Parwani.

Intussusception is the most common abdominal emergency for children under 2 years old. It occurs when one part of the intestine slides into an adjacent part of the intestine, blocking food or fluid from passing through. This can lead to perforation of the bowel or infection. Crying fits plus blood in the stool can be an indicator of intussusception.

Other issues that can affect children include inflammatory bowel diseases, Crohn's disease, and colitis.

“If a patient is experiencing fever plus severe abdominal pain, they should get checked out,” says Dr. Parwani.

Other signs that a patient should consider heading to the emergency room include:

• Sharp, severe, worsening pain
• Pain with walking or driving (due to bumps in the road), which “is a sign that there’s inflammation in the body,” Dr. Parwani says
• Nonstop vomiting and/or vomiting blood
• Blood in stool

At Yale Medicine’s Department of Emergency Medicine, the doctor's first step is to perform a physical examination when a patient complains of abdominal pain. The doctor will take the patient’s medical history and attempt to find the source of the pain or tenderness.

Several conditions can be diagnosed by blood tests, including inflammation in the liver and pancreas. Blood tests also allow doctors to check electrolyte balance and kidney function. Ultrasound allows the medical team to look at a patient’s gallbladder, kidneys, and aorta. Computerized tomography (CT) scans allow doctors to examine such solid organs as the appendix and liver.

“All of those tools are really important as we work toward figuring out if you have a dangerous cause of abdominal pain,” says Dr. Parwani. “They can’t diagnose more benign entities such as peptic ulcer disease, reflux or gastritis. Those are intraluminal, or inside the stomach itself, so ultrasound and CT scans won't see those.”

Emergency room doctors may also perform a routine endoscopy, in which a tube with a camera is inserted down the esophagus and into the digestive system to look at the stomach, in cases where something is stuck or there’s active bleeding.

Children experiencing abdominal pain may undergo an air or barium enema to assist in diagnosis.

When elderly people have abdominal pain, there is almost always something wrong, says Dr. Parwani, “particularly if the patient is over 70 years old.”

Imaging tests are nearly always ordered in cases of abdominal pain in the elderly.

At Yale Medicine, doctors work to relieve patients’ pain symptoms “from the moment they hit the door,” says Dr. Parwani.

Patients with peptic ulcer disease, reflux, or gastritis may require treatment with acid blockers and Maalox. Doctors will also work with patients to reduce vomiting and nausea to get the patient feeling more comfortable while they work to assess the problem.

In cases of gastritis or reflux, emergency room doctors will prescribe treatment to ease the symptoms and send the patient home. If tests reveal a more serious situation, such as an ectopic pregnancy or appendicitis, the patient will be referred to a Yale Medicine surgeon.

Yale Medicine emergency doctors treat every patient with attention and care to ease the pain and symptoms associated with abdominal pain.

“Even if you don't have a dangerous cause of abdominal pain, what we often are able to offer people is some relief from the symptoms,” says Dr. Parwani. “If you have gastritis, reflux or an ulcer, we certainly do provide medicine that will hopefully make you feel better.”