Acute abdominal pain can be caused by a number of conditions from benign and self-limiting to surgical emergencies. Evaluating abdominal pain requires an approach that relies on the likelihood of disease, patient history, physical examination, laboratory tests, and imaging studies. The location of pain is a useful starting point and usually guides further evaluation. For example, right lower quadrant pain strongly suggests appendicitis. Certain elements of the history and physical examination are helpful (e.g., constipation and abdominal distension strongly suggest bowel obstruction), whereas others are of little value (e.g., anorexia has little predictive value for appendicitis). Different imaging studies are recommended based on the location of pain. Ultrasonography is recommended to assess right upper quadrant pain, and computed tomography CT scan) is recommended for right and left lower quadrant pain. It is also important to consider special populations such as women, who are at risk of genitourinary disease, which may cause abdominal pain; and the elderly, who may present with atypical symptoms of a disease.
Abdominal pain is a common complaint and may be difficult to diagnose. Although most abdominal pain is benign, as many as 1 out of 10 patients that present to the emergency room with abdominal pain may have a life-threatening cause or require surgery. Therefore, a thorough and logical approach is necessary.
The doctor will focus on the common conditions that cause abdominal pain as well as the more serious possibilities. The location of pain will help drive the work-up. For example pain in the right lower quadrant is suggestive of appendicitis and pain in the right upper quadrant is suggestive of gallbladder problems (biliary colic). It is critical that the initial evaluation considers the possibility of a life-threatening diseases such as mesenteric ischemia, aortic aneurysm or dissection.
| Pain location | Possible diagnoses |
| Right upper quadrant | Biliary: cholecystitis, cholelithiasis, cholangitis |
| Colonic: colitis, diverticulitis | |
| Hepatic: abscess, hepatitis, mass | |
| Pulmonary: pneumonia, embolus | |
| Renal: nephrolithiasis, pyelonephritis | |
| Epigastric | Biliary: cholecystitis, cholelithiasis, cholangitis |
| Cardiac: myocardial infarction, pericarditis | |
| Gastric: esophagitis, gastritis, peptic ulcer | |
| Pancreatic: mass, pancreatitis | |
| Vascular: aortic dissection, mesenteric ischemia | |
| Left upper quadrant | Cardiac: angina, myocardial infarction, pericarditis |
| Gastric: esophagitis, gastritis, peptic ulcer | |
| Pancreatic: mass, pancreatitis | |
| Renal: nephrolithiasis, pyelonephritis | |
| Vascular: aortic dissection, mesenteric ischemia | |
| Periumbilical | Colonic: early appendicitis |
| Gastric: esophagitis, gastritis, peptic ulcer, small-bowel mass or obstruction | |
| Vascular: aortic dissection, mesenteric ischemia | |
| Right lower quadrant | Colonic: appendicitis, colitis, diverticulitis, IBD, IBS |
| Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID | |
| Renal: nephrolithiasis, pyelonephritis | |
| Suprapubic | Colonic: appendicitis, colitis, diverticulitis, IBD, IBS |
| Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID | |
| Renal: cystitis, nephrolithiasis, pyelonephritis | |
| Left lower quadrant | Colonic: colitis, diverticulitis, IBD, IBS |
| Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID | |
| Renal: nephrolithiasis, pyelonephritis | |
| Any location | Abdominal wall: herpes zoster, muscle strain, hernia |
| Other: bowel obstruction, mesenteric ischemia, peritonitis, narcotic withdrawal, sickle cell crisis, porphyria, IBD, heavy metal poisoning |
IBD = inflammatory bowel disease; IBS = irritable bowel syndrome; PID = pelvic inflammatory disease.
Although location of pain guides the evaluation, other signs and symptoms can be suggestive of certain causes of abdominal pain and can help narrow down the possible causes. For example, a patient with pain that moves from the belly button to the right lower quadrant, who has fever and significant right lower tenderness has to be evaluated for appendicitis.
If at all possible, the history should be obtained from the patient prior to giving him/her medications that may alter their ability to communicate, ie narcotics. It involves asking about the pain’s location, radiation, and movement. Additional information may be the onset, ie did the pain start 2 hours after eating a fatty meal, duration- how long has it lasted, severity- how bad is it, quality- is it a sharp pain or a dull ache, and are there any factors that make it better or worse.
Associated symptoms often allow the physician to further focus the list of possible diagnoses. For bowel obstruction, constipation, nausea and vomiting are the symptoms most suggestive. For appendicitis, right lower quadrant pain is the most suggestive, although pain migrating from periumbilical to right lower quadrant pain and fever is also suggests appendicitis.
Colic (i.e., sharp, localized abdominal pain that increases, peaks, and subsides) is associated with numerous diseases of hollow viscera. The mechanism of pain is thought to be smooth muscle contraction proximal to a partial or complete obstruction (e.g., gallstone, kidney stone, small bowel obstruction). Although colic is associated with several diseases, the location of colic may help diagnose the cause. The absence of colic is useful for ruling out diseases such as acute cholecystitis; less than 25 percent of patients with acute cholecystitis present without right upper quadrant pain or colic.
Peptic ulcer disease is often associated with Helicobacter pylori infection (75 to 95 percent of duodenal ulcers and 65 to 95 percent of gastric ulcers), although most patients do not know their H. pylori status. [Helicobactor pylori more commonly referred to as H. pylori is a bacteria in the stomach that can mach it easier to develop ulcers] In addition, many patients with ulcer disease and serology findings negative for H. pylori report recent use of nonsteroidal anti-inflammatory drugs (ie voltaren, ibuprofen, aleve, celebrex, aspirin). Other symptoms of peptic ulcer disease include concurrent, episodic gnawing or burning pain; pain relieved by food; and nighttime awakening with pain.
Symptoms in patients with abdominal pain that are suggestive of surgical or emergent conditions include fever, protracted vomiting, syncope or presyncope, and evidence of gastrointestinal blood loss.
The general appearance and vital signs can help determine the cause of abdominal pain. Most patient with peritonitis (an inflammation of the peritoneum, the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs) tend to avoid moving, whereas people with renal colic, ie kidney stones, tend to find it difficult to lay still. Fever suggests infection, but in the elderly or immunocompromised patients it may not be noticeable. Tachycardia (fast heart rate) and hypotension suggest hypovolemia from either blood loss, dehydration or septicemia.
There are several specialized maneuvers that evaluate for signs associated with causes of abdominal pain. When present certain signs are highly suggestive of certain diseases. Carnett’s sign is increased pain when a patient laying on his back tenses the abdominal wall by lifting the head and shoulders off the exam table. Pain on taking a deep breath when the examiner's fingers are on the approximate location of the gallbladder is known as Murphy’s sign. Pain on flexion/extension of the psoas muscle in the area of the appendix is suggestive of appendicitis.
Rectal and pelvic exam are recommended for patients with lower abdominal and pelvic pain. A pelvic exam may reveal vaginal discharge, cervical motion tenderness or peritoneal signs may suggest an infection or abscess in the Fallopian tubes or an ectopic pregnancy. It is important to ask any female of child bearing age when was her last period. A rectal exam may reveal a fecal impaction, a palpable mass, or gross blood.
Patients with abdominal pain usually will have blood drawn for a complete blood count (CBC) to evaluate the white blood cell count (WBC) which is increased with infection. Patients with epigastric pain should also have amylase and lipase levels drawn to evaluate for pancreatitis. Liver function tests are important in the evaluation of right upper quadrant pain/biliary colic. A urinalysis should be obtained in patients with hematuria, dysuria or flank pain. A urine pregnancy test should be obtained on any woman of childbearing age who presents with abdominal pain, prior to subjecting them to certain imaging studies. Testing for Chlamydia and gonorrhea is recommended for sexually active women.
Initial imaging studies are based on the location of abdominal pain. Plain radiography of the abdomen is often more readily obtainable and less expensive than ultrasonography or CT and can be helpful in several circumstances. An upright radiograph of the chest or abdomen can detect free air under the diaphragm, which indicates a perforation of the gastrointestinal tract. Abnormal calcifications also can be seen on a plain radiograph; this includes 10 percent of gallstones, 90 percent of kidney stones, and appendicoliths in 5 percent of patients with appendicitis. Plain radiography of the abdomen may help diagnose bowel obstruction with multiple dilated loops of the bowel and air-fluid levels, although similar findings may occur with paralytic ileus.
Ultrasound (U/S) is recommended for right upper quadrant pain. Computer tomography (CT) is recommended for right and left lower quadrant pain. In some patients with left upper quadrant pain, CT may be useful to evaluate the pancreas, spleen, kidneys, intestines, and vasculature.
Women of childbearing age present a specific challenge when making decisions about diagnostic imaging. Gynecologic causes of abdominal pain are more common in these women, and radiation exposure should be avoided if pregnancy is likely. Therefore, abdominal or transvaginal ultrasonography is generally recommended for evaluating left lower quadrant pain in women of childbearing age and in pregnant patients with right lower quadrant abdominal pain.
If ectopic pregnancy is suspected, transvaginal ultrasonography should be performed. The sensitivity of transvaginal ultrasonography for detecting ectopic pregnancy is 95 percent in a patient with a positive pregnancy test. Transvaginal ultrasonography is also helpful for diagnosing other gynecologic pathology, such as fibroids, ovarian masses, ovarian torsions, and tuboovarian abscesses
Several areas of the abdomen deserve special attention.
For right upper quadrant pain, the history focuses on differentiating pulmonary, urinary, and hepatobiliary pain. If urinary tract infection or nephrolithiasis is suspected, a urinalysis is appropriate. Patients with colic, fever, steatorrhea, or a positive Murphy's sign should receive ultrasonography.
The evaluation of right lower quadrant pain is guided by the patient's history. Patients with symptoms (e.g., fever, relocalization of pain) or signs (e.g., psoas sign, rigidity, rebound, guarding) suggestive of appendicitis should receive CT and urgent surgical consultation. Normal CT findings should trigger additional urine, colon, or pelvic examination.
Left lower quadrant pain focuses on evaluation for diverticulitis. Fever, previous diverticular disease, or suggestive physical examination findings (e.g., distention, tenderness, rectal blood) should prompt empiric therapy or CT. A normal evaluation should prompt further consideration of urinary or gynecologic pathology.
Patients with undiagnosed pain should be followed closely, and consultation with a surgeon should be considered early on in the process.
Future articles will focus on specific causes of abdominal pain.
