1 Abdominal Pain in Adults
Abdominal pain is the most common complaint seen in emergency departments in the United States and one of the 10 most common complaints in family medicine outpatient settings. The most common causes of abdominal pain are discussed here, with special attention given to the acute abdomen and recurrent abdominal pain. The term acute abdomen is medical jargon that refers to any acute condition within the abdomen that requires immediate medical or surgical attention. Acute abdominal pain may be of nonabdominal origin and does not always require surgery. The majority of patients who consult a physician about abdominal pain do not have an acute abdomen, although the chief complaint may have a sudden onset. In studies involving analysis of large series of patients presenting to emergency departments with acute abdominal pain, nonspecific abdominal pain (NSAP) was the most common diagnosis. Most patients with this symptom probably have gastroenteritis.
The common causes of abdominal pain are gastroenteritis, gastritis, peptic ulcer disease, gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), dysmenorrhea, salpingitis, appendicitis, cholecystitis, cholelithiasis, intestinal obstruction, mesenteric adenitis, diverticulitis, pancreatitis, ureterolithiasis, incarcerated hernias, gas entrapment syndromes, and ischemic bowel disease (particularly in the elderly). All of these conditions can manifest as an acute or sudden onset of abdominal pain, many can cause recurrent abdominal pain, and a few require surgical intervention. Any acute abdominal condition requires the physician to make an early, precise diagnosis, because prognosis often depends on prompt initiation of therapy, particularly surgical treatment. The more serious the problem, the more urgent the need for an accurate diagnosis.
The examiner can best establish a complete and accurate diagnosis by carefully noting the patient’s age, gender, and past medical history; precipitating factors; location of the pain and of radiating discomfort; associated vomiting; altered bowel habits; chills and fever; and findings of the physical examination, particularly of the abdomen. Abdominal pain without other symptoms or signs is rarely a serious problem. The presence of alarm signs (weight loss, gastrointestinal [GI] bleeding, anemia, fever, frequent nocturnal symptoms, or onset of symptoms in patients older than 50 years) suggests a serious problem.
The physician must be especially aware of the conditions that cause abdominal pain and usually require surgical intervention. According to one large study, the most common conditions requiring surgical intervention are appendicitis, cholecystitis, and perforated peptic ulcer. Others are acute intestinal obstruction, torsion or perforation of a viscus, ovarian torsion, tumors, ectopic pregnancy, dissecting or ruptured aneurysms, mesenteric occlusion, bowel embolization, and bowel infarction.
Several authorities warn against the practice of pattern matching in the diagnosis of acute abdominal surgical conditions; they have discovered that there are typical findings in only 60% to 70% of patients. This means that if physicians attempt to match acute problems with patterns or stereotypes of the disease, they will fail to make the correct diagnosis in 30% to 40% of cases. Therefore, to improve diagnostic accuracy, physicians must know the standard and typical presentations and must also be aware of the subtleties involved in the differential diagnosis. The best-test method is more accurate than pattern matching in establishing the diagnosis.
The best-test method involves elicitation of specific information that correlates well with the correct diagnosis. This method suggests that when a specific symptom or physical sign is noted, its presence is highly useful in establishing the correct diagnosis. For instance, the finding of pain in the right upper quadrant (RUQ) most frequently suggests cholecystitis. Likewise, if pain is aggravated by movement, it most frequently indicates appendicitis but also suggests perforated peptic ulcer to a lesser degree. A best-test question used to differentiate the most common causes of abdominal pain—NSAP and appendicitis—is whether the pain is aggravated by coughing or movement. The pain of appendicitis is aggravated by movement or coughing, whereas the pain of NSAP is not. Abdominal pain that is aggravated by movement or coughing is probably caused by peritoneal inflammation. Best-test signs that are helpful in differential diagnosis include the presence of a palpable mass in diverticular disease, hyperactive bowel sounds in small-bowel obstruction, reduced bowel sounds in perforation, and involuntary guarding in the right lower quadrant (RLQ) in appendicitis. The validity of best-test findings has been supported by retrospective studies in which the diagnosis is known.
It is often difficult for the physician to elicit an accurate description of the nature of the pain in elderly patients. They may be unable to distinguish new symptoms from preexisting complaints and concomitant illnesses. Many elderly patients present late in their illnesses, often after treating themselves for indigestion or constipation. In contrast to the high frequency of appendicitis, cholecystitis, and perforated ulcers in most general surgical series, the most common causes of acute surgical abdomen in patients older than 70 years are strangulated hernias (45%) and other forms of intestinal obstruction (25%).
In several studies, both the primary diagnosis and the discharge diagnosis in elderly patients with acute abdominal pain were less reliable than those in younger patients. Elderly patients are found to have organic disease more often than younger patients, possibly justifying more liberal use of radiologic studies in the older population.
The physician must remember that cancer is a common cause of abdominal pain in the elderly. In a study of patients older than 50 years with NSAP, 10% had cancer, the majority of whom had large-bowel cancer. Colon cancer is almost as common as perforated peptic ulcer, pancreatitis, and renal colic in patients over age 50. Cancer should be strongly suspected if the patient is older than 50 years and has had previous bouts of unexplained abdominal pain, if the present abdominal pain has lasted at least 4 days, and if constipation is present.
The person’s age also offers clues to diagnosis in other groups of patients. Appendicitis has its peak incidence in the second decade, although it can occur in patients older than 60 years as well as in infants. The incidence of cholecystitis increases with age and is the most frequent cause of acute abdominal pain in patients older than 50 years.
Cholecystitis is more common in whites than in blacks, more prevalent in females than in males, and more common in women who take oral contraceptives or estrogens than in those who do not. Drugs that increase cholesterol saturation also increase the incidence of cholelithiasis. They include gemfibrozil, fenofibrate conjugated estrogens, and estrogen-progestin combinations.
NSAP is an imprecise diagnosis, yet it is the most common diagnosis given to patients presenting to an emergency department with abdominal pain as the chief complaint. This diagnosis is most common in patients younger than of 40 years.
Irritable bowel syndrome seems to be most common in young women, particularly those who have young children. This frequency has been attributed to the life pressures to which these women are subjected. Symptoms of irritable bowel are also more frequent in others under stress, including children. The abdominal pain from an irritable bowel may be a vague discomfort or pain in the left lower quadrant (LLQ), RLQ, or midabdomen. It occasionally radiates to the back. This pain may be relieved by defecation and may be associated with other well-recognized symptoms of irritable bowel: mucus in the stool, constipation alternating with diarrhea, and small marble-like stools.
Lower abdominal or pelvic pain in women is often difficult to evaluate. Ectopic pregnancy, ovarian torsion, ruptured ovarian cyst, pelvic inflammatory disease, endometriosis, and mittelschmerz must always be kept in mind. It has been suggested that all young women with lower abdominal pain be tested for Chlamydia. Surgical emergencies of gynecologic origin are more common in women of reproductive age and include pelvic inflammatory disease with abscess, ectopic pregnancy, hemorrhage from an ovarian cyst, and adnexal or ovarian torsion.
Peptic ulcer pain is most common between ages 30 and 50 years but may occur in teenagers and, rarely, in young children. It is considerably more common in men than in women. However, this diagnosis should not be entirely disregarded in women because a significant incidence of perforated peptic ulcer among women may be a result of physicians’ failure to consider peptic ulcer in the diagnosis. Although only 15% of patients with ulcer symptoms are older than 60 years, 80% of deaths from ulcers occur in this group, because ulcer disease in elderly patients is more likely to run a virulent course.
Acute intestinal obstruction occurs in all age groups. In the elderly, intestinal obstruction is usually caused by strangulated hernias or cancer. However, in any patient with severe abdominal pain and a history of abdominal surgery, adhesions constitute the most likely cause of intestinal obstruction.
Pancreatitis occurs most frequently in alcoholic patients and patients with gallstones. Sigmoid volvulus is more common in males, patients with cognitive disabilities, and patients with parkinsonism; cecal volvulus is more common in females. Gallstone ileus causes small-bowel obstruction more often in the elderly and in women. Mesenteric adenitis is more common in children. Peptic esophagitis is more common in obese patients. The incidence of diverticulitis increases with age; this disorder is more common after age 60.
Classically, biliary colic develops in the evening and is usually a steady midepigastric or RUQ pain. Colicky or crampy pain that begins in the midabdomen and progresses to a constant pain in the RLQ suggests appendicitis. Other conditions that may begin in a crampy or colicky manner and progress to a more constant pain include cholelithiasis and cholecystitis (which tend to localize in the RUQ), intestinal obstruction, and ureterolithiasis (which involves excruciating pain that frequently radiates to the groin, testes, or medial thigh).
A constant, often annoying burning or gnawing pain located in the midepigastrium and occasionally associated with posterior radiation is seen with peptic ulcer. Peptic ulcer pain may be worse at night, although this pattern is unusual. The pain is not ordinarily made worse by recumbency. The pain of peptic ulcer in elderly patients may be vague and poorly localized. Because of a lack of classic symptoms, an occasional absence of prior symptoms, and a confusing picture of abdominal pain, perforation associated with peritonitis is more common in older patients. It is particularly important to note that pain induced by percussion in the epigastrium may be the only physical finding to suggest ulcer disease in a person complaining of typical peptic ulcer pain. Likewise, severe exacerbation of pain that occurs when the physician percusses over the RUQ strongly suggests the presence of an inflamed gallbladder.
The Rome II criteria (12 weeks of symptoms in the preceding year; a change in the frequency or form of the stool, bloating, and pain that is usually dull, crampy, and recurrent) suggest irritable bowel syndrome. It is often associated with constipation that alternates with diarrhea, small stools, and mucus in the stools. In addition, moderate pain may be elicited when the physician palpates the colon. However, in elderly patients, severe diverticulitis may exist with similar symptoms.
Most abdominal pain, even when severe, usually develops over several hours. When the onset of severe abdominal pain is abrupt, it suggests perforation, strangulation, torsion, dissecting aneurysms, or ureterolithiasis. The most severe abdominal pain occurs with dissecting aneurysms and ureterolithiasis. The pain of a dissecting aneurysm is often described as a tearing or ripping sensation and frequently radiates into the legs and through the torso to the back. Such pain usually manifests in patients who are in profound shock. Individuals with the excruciating pain of ureterolithiasis may be writhing in agony but do not experience cardiovascular collapse. The pain of ureterolithiasis is usually unilateral in the flank, groin, or testicle and is often associated with nausea and occasional vomiting.
The location of the pain is one of the best tests for determination of a diagnosis (Fig. 1-1). RUQ pain is most frequently seen in cholecystitis, cholelithiasis, and leaking duodenal ulcer (Fig. 1-2). Another clue to gallbladder disease is the radiation of RUQ pain to the inferior angle of the right scapula. RUQ pain is also seen in patients with hepatitis or congestive heart failure. In the latter group the pain is thought to be caused by swelling of the liver, which results in distention of Glisson’s capsule. Myocardial infarction may manifest as RUQ pain. Less severe RUQ pain may be seen in patients with hepatic flexure syndrome (gas entrapment in the hepatic flexure of the colon). If questioned carefully, these patients will admit to experiencing relief with the passage of flatus.
(From Schwartz S: Principles of Surgery, 2nd ed. New York, McGraw-Hill, 1974, p 972.)