Chronic abdominal pain occurring over a period of weeks to months in the absence of any alarm signs or symptoms may be less urgent, allowing for a more systematic evaluation. Chronic intermittent pain may, at times, be particularly difficult to diagnose whereas chronic persistent pain usually has an identifiable cause, such as chronic pancreatitis, disseminated malignancy, or severe inflammatory bowel disease. Examples of conditions causing intermittent abdominal pain, often associated with meals, include gastroesophageal reflux disease, peptic ulcer disease, biliary tract disease, and chronic pancreatitis. Pain that is temporally associated with a woman’s menstrual cycle may be due to endometriosis or ovulation. Chronic pain associated with anorexia and weight loss may indicate an underlying malignancy. The symptoms of irritable bowel syndrome, a functional disorder characterized by abdominal discomfort or pain associated with an alteration in bowel habit, are often precipitated or worsened by stress or anxiety. Chronic intractable abdominal pain (CIAP) is another functional disorder seen predominantly in women, often with a history of sexual or physical abuse, in which pain is longer than 6 months in duration and organic causes have been excluded.
Although abdominal pain may not be as precisely localized as it is elsewhere (e.g., the skin), the location of pain may provide some useful clues. Traditionally, the abdomen is divided into four parts, referred to as the patient’s right upper, left upper, right lower, and left lower quadrants. Other locations of clinical importance are the epigastrium (in the central upper abdomen), periumbilical area (around the umbilicus or navel), and suprapubic area (below the umbilicus and above the pubic bone). Pain arising in the right upper quadrant may represent acute cholecystitis (inflammation of the gallbladder) or hepatitis. Pain in the left upper quadrant may be due to impaired blood flow to the spleen or left colon. Pain caused by appendicitis often begins in the periumbilical area and then settles in the right lower quadrant. Pain due to disorders involving the kidneys, ovaries, or fallopian tubes is usually perceived on the same side of the abdomen as the affected organ. Because diverticulosis most often involves the sigmoid colon, which is located in the left lower quadrant, the pain of diverticulitis (acute diverticular inflammation) is usually perceived in this region. Suprapubic pain may be seen in urinary tract infections, pelvic inflammatory disease, and endometriosis. Central abdominal pain may be due to gastroenteritis, peptic ulcer disease, or acute pancreatitis. Diffuse abdominal pain may represent infectious peritonitis, appendicitis, inflammatory bowel disease, or a perforated duodenal ulcer.
An important feature of abdominal pain is the tendency for pain to be located at a site remote from the affected organ. The term for this is referred pain. For instance, pain from an inflamed gallbladder may sometimes be perceived in the right shoulder. Abdominal pain may also radiate, for example, the epigastric pain from pancreatitis may radiate to the back; and flank pain from a kidney stone may radiate to the groin.
A careful, gentle physical examination plays a vital role in the physician’s evaluation of abdominal pain and is often more informative than laboratory studies. The clinician assesses the general appearance of the patient along with the vital signs. Alarm signs including confusion, restlessness, sweating, rapid heart rate, drop in blood pressure, or high fever usually dictate urgency in the evaluation. A history of abdominal pain associated with unresponsiveness, shock, or cardiac arrest suggests that a catastrophic abdominal event has occurred that requires emergent treatment. The presence of abdominal distention, scars, rashes, bruising, or hernias may aid in the diagnosis. Absence of bowel sounds (after listening for at least 1 min) may indicate the presence of an ileus (the failure of intestinal contents to pass through the gastrointestinal tract in the absence of an anatomical obstruction), whereas hyperactive or high-pitched tinkling sounds suggest intestinal obstruction. Guarding (involuntary abdominal muscular wall contraction) on palpation suggests the presence of peritonitis. The abdomen is also examined for the presence of masses as well as liver and spleen findings such as enlargement, nodularity, or tenderness. In women with lower abdominal pain, a pelvic examination should be performed to assess potential uro-gynecological causes. Tenderness, blood, or a mass lesion found on rectal examination provides other important diagnostic information.
Laboratory and radiologic studies can provide additional information in making the diagnosis. Specific tests ordered should reflect the clinical suspicion. In general, a complete blood count, serum chemistries, and urine studies are performed. A pregnancy test should be considered in all women of reproductive age with lower abdominal pain. Other laboratory tests, including stool studies, liver function tests, amylase, and lipase, are ordered when clinically appropriate.
A variety of diagnostic imaging tests are available which may aid in the evaluation of abdominal pain. Plain x-rays of the abdomen, in upright and supine (lying down) positions, is obtained when perforation or bowel obstruction are suspected. Ultrasonography is useful in the evaluation of the liver, biliary tract, spleen, kidneys, and tubo-ovarian system. Doppler technology allows evaluation of the large vessels. Computed tomography (CT), the most versatile imaging tool, is highly sensitive for the detection of inflammatory, neoplastic, and vascular lesions, as well as for identifying obstruction, perforation, and fluid collections. Other potential radiologic examinations available, depending on the clinical circumstances, include angiography, contrast imaging, nuclear medicine scans, or magnetic resonance imaging (MRI). Clearly the specific management of abdominal pain will vary greatly depending on the acuity and cause. The evaluation and treatment of both acute and chronic abdominal pain often require input from a number of medical/surgical specialists including surgeons, obstetrician/gynecologists, and gastroenterologists. The decision of which specialist(s) to involve and when is dictated by the clinical circumstances. Surgeons perform not only a great number of curative operative procedures, but also both invasive (e.g., exploratory abdominal surgery) and minimally invasive diagnostic (e.g., laparoscopy) procedures.
Obstetrician/gynecologists are skilled in the evaluation of women with a suspected gynecologic cause of pain and perform a wide variety of diagnostic and curative procedures such as transvaginal ultrasound, diagnostic and therapeutic laparoscopy, and a number of other pelvic surgical procedures. Gastroenterologists offer a variety of procedures for the diagnosis and treatment of abdominal pain including upper and lower endoscopy (insertion of a flexible tube containing a camera into the mouth or rectum) of the digestive and pancreas-biliary tracts, motility studies, and pH (acid) monitoring.
Chronic abdominal pain is often difficult to diagnose and treat. At times, the involvement of an anesthesiologist or other pain management professional is helpful. They are skilled in the management of pain with medications, therapeutic nerve blocks (injection of an anesthetic agent near a specific nerve or group of nerves), and counseling. If there appears to be a psychiatric component to abdominal pain, referral to a mental health professional is appropriate. Chronic functional abdominal pain syndromes require a combined approach of education, reassurance, dietary changes, medications, and, at times, behavioral therapies (e.g., relaxation and biofeedback techniques).