Captain Jeffrey J. McInturff, MD, US Army
Darnall Army Community Hospital
Fort Hood, Texas

In our discussion of abdominal pain, we will first need to focus on the history and physical exam, including the signs of an "acute abdomen." Then we will address the various "quadrants" and the various disorders commonly associated with each. We will briefly discuss how extremes of age and pregnancy can affect the patient's presentation and evaluation. Then, toward the end of our discussion but before our conclusion, we will address the possibility of referred pain.

The patient's general appearance and degree of distress can tell a physician a great deal about the etiology of the patient's pain. A patient who is comfortably sitting and chatting with loved one's will typically have a benign etiology, enabling one to exclude a AAA or a perforated viscus. A patient who is writhing, unable to find a position of comfort, is often plagued with a renal or biliary stone. In converse, the patient who refrains from movement, preferring to lie still, often has signs of peritoneal irritation. Meanwhile, the patient lying in the fetal position with a bucket of emesis not too far often has crampy gastroenteritis.

Age is very important. As we will discuss later, certain disorders are more prevalent among certain age brackets. Twenty one year-olds do not suffer from mesenteric ischemia or acute abdominal aneurysms.

Pain is the chief complaint. Its location will help you to isolate a quadrant. Its duration and time of onset are further very helpful as appendicitis rarely presents with 7-10 days of pain. The quality and severity are also very helpful -- but allowance must be made for the variations in patient's descriptions.

Vital signs are essential in any evaluation of abdominal pain. They serve as objective data to support or question your final diagnosis. A fever can suggest an infectious etiology, but it's absence alone can not rule out infection. The pulse and blood pressure can identify hemorrhage, dehydration, pain or sepsis.

GI symptoms are also helpful in identifying an etiology with diarrhea being more specific than vomiting and nausea, which can also be seen in pyelonephritis and myocardial infarctions. Anorexia is commonly seen with appendicitis, but its absence doesn't rule out appendicitis. Passage of flatus helps to rule out bowel obstruction. Blood in the stool is often seen with diverticulitis and intussusception.

A new vaginal discharge can help to identify pelvic inflammatory disease. Similarly, vaginal bleeding is often seen during pregnancy and can signify an ectopic pregnancy or a threatened miscarriage. A menstrual history can identify both mittelschmerz and pregnancy prior to laboratory confirmation.

Symptoms of frequency, dysuria and urgency, while most specific for urinary tract infections, can also occur as a result of inflammation near the bladder or ureters. These symptoms in conjunction with fever, nausea/vomiting, and flank pain suggest advancement to pyelonephritis. Hematuria may suggest cystitis or nephrolithiasis.

Respiratory symptoms are often overlooked. Many patients have presented with complaints of abdominal pain only to be discharged with the diagnosis of pneumonia, which was incidentally discovered by the CXR in the abdominal series ordered by the physician. These pneumonias are often basilar but may also be diffuse. Hence, a history of cough or respirophasic pain (pleurisy) should be elicited.

After obtaining the history, the physician examines the patient. While the abdominal exam is emphasized, a cardiac and pulmonary exam must also be performed.

First the physician observes for peristalsis, distension, and abdominal scars. Then listening for bowels sounds, the physician may identify an ileus or the rushing peristalsis of a bowel obstruction. Then the patient is asked to identify the location of the pain. After the patient does this, the physician should gently percuss the abdomen, searching for signs of peritoneal irritation, but starting first away from the focus of pain and gingerly moving towards it. Similarly with palpation, the physician should start away from the focus of pain, searching for masses and points of tenderness. If the patient is female, a pelvic examination may also be necessary. Occasionally the pelvic exam may be omitted - but typically only when the examiner is well experienced and the etiology of the abdominal pain is obvious.

There are a variety of other maneuvers during examination which are crucial:

Costo-vertebral angle tenderness can often suggest pyelonephritis. However, if the patient has evidence of peritoneal irritation on abdominal exam, this is often falsely positive.

Femoral pulses may or may not be equal with an abdominal aneurysms. Equality of pulses does not effectively rule out the diagnosis, but inequality is certainly suggestive.

A rectal examination can assist with the identification of a pelvic appendix, diverticular disease and bowel obstruction secondary to cancer or intussusception.

Checking the male genitalia for pain can identify referred pain from the testes. Further, by looking for hernias, one may be able to identify the cause for a patient's bowel obstruction.

The heel tap identifies peritoneal irritation. The obturator sign can identify inflammation local to the obturator foramen. The psoas sign identifies inflammation local to the psoas muscle.

The "acute abdomen" is a term typically used to describe an abdomen which is firm and diffusely tender. An abdomen may become firm as a result of voluntary or involuntary guarding. Voluntary guarding occurs secondary to patient apprehension during the physical exam. Involuntary guarding is a result of diffuse peritonitis. Diffuse rebound tenderness and tenderness to percussion are further signs of an "acute abdomen." Processes like appendicitis may produce localized peritoneal irritation and parietal pain but rarely produce a firm, rigid abdomen with diffuse tenderness unless perforation has occurred.

Unlike parietal pain which produces relatively well localized discomfort, visceral pain is often experienced distant from its source. Visceral pain can therefore mislead a physician by directing him or her away from the offending disorder.

Distension can produce visceral pain. This is often seen in small bowel obstruction, gastroenteritis, early appendicitis, etc.

Ischemia can also produce visceral pain. This occurs with mesenteric thrombosis.

1. For the right upper quadrant, one must consider biliary or peptic ulcer disease.

2. For the left upper quadrant, one must consider pancreatitis or peptic ulcer disease.

3. For the right lower quadrant: appendicitis, acute salpingitis, ectopic pregnancy.

4. The left lower quadrant: diverticulitis, acute salpingitis and ectopic pregnancy.

5. Flank pain should prompt consideration of pyelonephritis, nephrolithiasis, and pneumonia.

6. Diffuse or central discomfort suggests gastroenteritis, abdominal aneurysm or mesenteric ischemia.

The biliary tract can cause numerous disorder, each of which presents differently:

Acute cholecystitis entails RUQ tenderness and an elevation of either the WBC or the patient's temperature.

Ascending cholangitis occurs with fever, jaundice and shaking chills. This occurs as a result of a biliary tree infection extending up into the liver. It is a surgical emergency as it is often the result of a common bile duct stone.

Cholelithiasis and choledocholithiasis are simply known as "biliary colic." Here the patient experiences intermittent midline, visceral pain. The gallbladder has not developed any inflammation (yet.)

Peptic ulcer disease is often experienced in the epigastrium or either of the two upper quadrants.

Patients typically describe the pain as "burning" with frequent radiation toward the back. Patients often have a history of similar pain previously that has responded to antacids or over-the-counter drugs.

If the patient has a gastric ulcer, their pain typically occurs immediately after the meal, as the gastric juices irritate the ulcer.

If the patient has a duodenal ulcer, their pain often occurs a couple of hours after a meal, when the stomach contents spill into the duodenum and irritate the ulcer there.

The pain of pancreatitis is described as excruciating and can be localized to the epigastrium or LUQ. The onset may be sudden and it often radiates towards the patient's back. The physician may also see: fever (even without abscess formation), vomiting, shock.

The patient's age can often identify the etiology with the elderly frequently developing pancreatitis secondary to biliary obstruction and the young (and restless) secondary to alcoholism.

Ranson's criteria are helpful prognostically but of no help diagnostically. An elevated amylase and lipase (more specific) are usually diagnostic.

The LUQ is the quadrant which disturbs patients and physicians most infrequently.
With any history of recent trauma, one must consider the possibility of a splenic injury. The physician may see tachycardia, an elevated WBC, and a concomitant complaint of left shoulder pain (Kehr's sign.)

Of course, with a history of sickle cell disease, one must consider splenic infarction.

Both the history and physical exam are crucial in the diagnosis of appendicitis. Many patients will either present with or have a history of initial periumbilical (midline) discomfort. This is the poorly localized visceral discomfort which occurs secondary to distension of the appendix.

After several hours of the midline visceral pain, the patient then typically experiences sharp RLQ pain. This new focus of pain is parietal in origin, resulting from peritoneal irritation.

Aside from the complaint of pain, the patient may also have varying degrees of nausea, vomiting, diarrhea, anorexia, and constipation.

Laboratory tests, while always obtained, are of limited value when pursuing appendicitis as a possible diagnosis. Hence, the diagnosis is made by history and, if necessary, repeated physical examinations.

The temperature and the WBC may be either very normal or very high.

While radiographs may occasional confirm the diagnosis with a fecolith in less than 10% of patients with appendicitis, x-rays usually serve to exclude other diagnosis.

The appendix located in the pelvis can be a diagnostic challenge for the clinician. While the patient typically experiences the midline, visceral pain, he or she may not develop the parietal, localizing component due to absence of peritoneal irritation.

Symptoms of a UTI may be prominent with frequency and dysuria. The patient may also experience non-voluminous diarrhea or tenesmus.

The rectal exam may elicit tenderness (usually along the right rectal wall.) Or, the obturator sign may be positive, again -- owing to the position of the appendix.

As a result of the difficulty in this diagnosis, perforation occurs more frequently.

Ectopic pregnancy is seen with increasing frequency, now accounting for 1.5% of all pregnancies.

Of the women presenting with this eventual diagnosis, pain was the most frequent complaint and it may localize to either the right or left lower quadrant. Many will note recent amenorrhea (suggesting pregnancy.) About 3/4 will also have concomitant vaginal bleeding. The absence of GI complaints is occasionally helpful in distinguishing this disorder from appendicitis (though not perfectly.)

A pregnancy test and a recent menstrual history are important.

A vaginal ultrasound is frequently required to confirm an intrauterine pregnancy and to differentiate that tender corpus luteum cyst from an ectopic pregnancy.

Pelvic inflammatory disease is usually bilateral with an insidious onset and an absence of GI symptoms.

The patient will frequently admit to a change in her vaginal discharge and should have either cervical motion tenderness or adnexal tenderness on bimanual examination.

The patient should also have one of the following: a WBC > 10,000, a temperature > 38 degrees Celsius, an inflammatory mass by exam or sonography or purulent discharge on laparoscopy.

The patient with diverticulitis typically presents with a deep, constant pain and localized tenderness anywhere along the colon's course, but usually in the LLQ.

Like the pelvic appendix, the patient may have tenesmus and rectal tenderness.

There is often a change in the patient's bowel habits -- either diarrhea or constipation. And, as alluded to previously, dysuria and frequency may occur secondary to inflammation around the urinary bladder. A fistula with the bladder can often produce pneumaturia.

Nausea and vomiting are occasionally seen. The fever is usually low-grade and the WBC is mild or moderately elevated.

Frequency, urgency and dysuria are frequent symptoms of urinary tract disease.

UTIs are simple to diagnose and treat. The hazard is when the disease progresses to pyelonephritis and GI symptoms develop.

Always remember during an evaluation of abdominal pain that numerous disorders can produce urinary tract symptomatology and dirty urines.

Having discussed the various quadrants of the abdomen and the particular disorders acquainted with each, some important points regarding both age and pregnancy require mention. The patient's age will influence both the clinician's differential and the patient's physical exam. The physical examination can often appear falsely benign in the elderly population as many of these patients do not develop signs of peritonitis until very late in the disease's course.

In the elderly, the clinician should be watchful for diverticulitis and both mesenteric ischemia and AAA.

In the adolescent, mittelschmerz, salpingitis and ectopic pregnancy are far more likely.

Mesenteric ischemia produces visceral pain from infarction of the patient's bowels. The pain is typically dull and poorly localized with a possible history of "angina," pain following meals.

These patients often complain of severe pain but have benign exams. Hence, the pain is classically out of proportion to the physical findings.

If the patient suffers from atrial fibrillation then he or she may have thrown a clot into the superior mesenteric artery producing the sudden onset of symptoms. Patients with gradual thrombosis of same vessel will usually describe a gradual onset with a history of aforementioned post-prandial pain.

If the ischemia is the result of thrombosis, the patient may have a history of weight loss or changing bowel habits. This occurs as a result of the patient's avoidance of food and ischemic dysfunction of the GI tract.

Acute abdominal aneurysms usually occur in the 6th and 7th decades of life.

The patients often have a cardiac history or suffer from similar risk factors like hypertension, tobacco use, hyperlipidemia, diabetes, and male gender.

The diagnostic triad is abdominal or back pain, a pulsatile mass and hypotension. However, the patient may present with the sole complaint of back pain with normal vital signs and a normal exam.

Much like mesenteric ischemia, the key is a high index of suspicion.

Appendicitis during pregnancy is a difficult disease. It is more difficult to diagnose, producing many delays, and is fraught with complications. Thankfully, it is seen with the same frequency as in the general population. During pregnancy, the position of the appendix shifts and the symptoms associated with appendicitis are less specific and less reliable in the pregnant population. There is a normal leukocytosis of pregnancy which even undermines the WBC as a laboratory adjunct in this diagnosis.

With regard to cholecystitis, the incidence actually increases during pregnancy as a result of incomplete gallbladder emptying following meals.

Obviously, ectopic pregnancy is only found in pregnant females.

If a patient presents to the emergency department with the complaint of back pain, one must consider/entertain the possibility of referred abdominal pain from such causes as pancreatitis or an acute abdominal aneurysm.

Similarly, shoulder pain with an unimpressive shoulder examination should make one consider biliary disease.

Testicular or groin pain can possibly be secondary to urolithiasis.

While abdominal pain can be referred to other parts of the body, the reverse is possible as well. Patients with epigastric discomfort may actually be suffering from a myocardial infarction, a pulmonary embolus, or a basilar pneumonia.

Testicular pain can also be felt in the abdomen.

When all is said and done, about 50% of ED patients will leave without a precise explanation for their abdominal pain. In the vast majority of cases, their discomfort resolves spontaneously without our assistance. That's okay. Our task is to determine who is really sick and who can benefit from antibiotics or a surgeon.

Repeat examination is an important modality which should be relied upon if the dispositioning physician has any reservations. Changes in physical examination can often provide crucial clues as to the etiology of your patient's pain.