Resident Editor: Scott Goldberg, MD, Myung Ko, MD

Faculty Editor: Ryan Laponis, MD

Background

• Abdominal pain is the most common cause for hospital admission in the United States
•  Diagnoses range from the benign to the life-threatening

Signs and Symptoms

• The pivotal clues in diagnosing abdominal pain include:
  • Location: What quadrant is the pain located?
  • Time course: Is it acute, subacute, or chronic? Is it the first-time or recurrent?
  • Assessing for peritoneal findings (pain with minimal movement)
  • Assessing for abdominal distension   
• Other important clues include:
  • Vital signs
  • Factors that make the pain better or worse
  • Radiation
  • Prior abdominal surgeries
  • Associated symptoms such as nausea, vomiting, anorexia, hematochezia, hematemesis, melena, change in stool caliber, fevers, chills, weight loss
  • Sexual and menstrual histories are important in women
  • Use of alcohol, NSAIDs, OTC meds, injection drug use
  • Pallor, jaundice, scleral icterus
  • Pulmonary or cardiac symptoms
     

Differential Diagnosis

Acute Abdominal Pain Requiring Emergent Referral

• Peritonitis
  • Rigidity, involuntary guarding, and hypoactive bowel sounds result from peritoneal inflammation
  • Often associated with systemic signs and symptoms such as fevers, chills, night sweats, and leukocytosis
  • Consider appendicitis, diverticulitis, perforated viscus (perforated peptic ulcer, perforated bowel, splenic rupture)  
  • Peritonitis may be masked in patients on chronic immunosuppression (even daily steroids), with chronic diseases (CKD and diabetes), and the elderly
• Obstruction
  • Small or large bowel obstruction
  • Anorexia, nausea, vomiting, obstipation, and decreased flatus result from luminal obstruction in the setting of structural abnormalities
  • Have a high index of suspicion in patients with a history of multiple abdominal surgeries, active malignancy, Crohn's disease, or elderly age (for large bowel)
  • Pseudo-obstruction may occur in the setting of chronic opiate use or spinal cord injury
• Cholecystitis, cholangitis, or acute pancreatitis
  • All can present with right upper quadrant and/or epigastric pain associated with nausea or vomiting
  • Murphy's sign is highly sensitive for acute cholecystitis, though this may be diminished in the elderly
  • The triad of fever, jaundice, and right upper quadrant pain is a late sign of complete biliary obstruction and its absence does not rule out serious pathology
  • Have a high index of suspicion in patients with severe or persistent pain especially if fever or anorexia is present
• Abdominal aortic aneurysm (AAA)
  • Expanding AAA may cause nonspecific abdominal, back, or flank pain
  • Risk factors include male gender, age, and smoking 
  • Pulsatile abdominal mass may be present on exam
  • Ruptured AAA often presents with acute, severe abdominal pain, hypotension, and syncope
• Acute mesenteric ischemia
  • Acute onset of severe, diffuse abdominal pain that is often out of proportion to the physical exam due to acute occlusion of the mesenteric vasculature
  • May be accompanied by nausea or vomiting
  • Peritoneal signs are often absent
  • Risk factors include atherosclerosis, atrial fibrillation, heart failure, valvular heart disease, catheterization, intra-abdominal malignancy, and prior embolic event
• Acute coronary syndrome
  • Referred pain from above the diaphragm can present as acute abdominal pain that may be exertional in nature
  • Have a high index of suspicion in patients with atherosclerosis, diabetes, and female gender
• Gynecologic emergencies
  • Have high index of suspicion for ectopic pregnancy, tubo-ovarian abscess, ovarian torsion in a young woman with left or right lower quadrant pain

Diagnoses Not Requiring Emergent Referral

• Peptic ulcer disease
  • 80% present with epigastric pain
  • May be food-provoked (worse after meals and associated with nausea and fullness) or worse with fasting (burning pain between meals relieved by food and antacids)
  • May also be associated with a sensation of reflux (See PUD chapter)
• Functional dyspepsia
  • Most common cause of abdominal pain seen in primary care
  • Presents with chronic postprandial fullness, early satiety, and epigastric pain or burning
  • By definition will have no structural abnormalities on endoscopy
• Biliary colic
  • Dull, pressure-like, constant pain that may radiate to back and R scapula
  • Presents as chest pain in up to one third of patients
  • Follows ingestion of a fatty meal by one to two hours and gradually improves over several hours
  • Often associated with nausea, vomiting, and diaphoresis
  • Pain that is persistent or associated with fever should raise suspicion for acute cholecystitis
• Acute viral hepatitis
  • Presentation can vary from mild flu-like illness to fulminant hepatitis
  • Can see fatigue, malaise, nausea, vomiting, anorexia, fever, and RUQ pain
  • May develop dark urine, acholic stools, jaundice, and pruritus
  • Jaundice and hepatomegaly are the most common exam findings
• Irritable bowel syndrome
  • Often diffuse, crampy pain associated with diarrhea, constipation, or both and relieved by defecation; can be exacerbated by diet and stress
  • Severe abdominal pain, large volume diarrhea, malnutrition, or signs of systemic illness should prompt a search for an alternative diagnosis (see chapter on IBS)
• Inflammatory bowel disease (IBD)
  • Chronic crampy abdominal pain is more often characteristic of Crohn’s disease than ulcerative colitis (UC)
  • In Crohn’s disease, pain is often from strictures and transient bowel obstruction
  • Focal pain may reflect the underlying location of pathology (i.e. RLQ pain due to terminal ileitis or rectal pain due to abscess)
  • Often associated with chronic diarrhea, which is only sometimes grossly hemorrhagic
    • UC presents with hematochezia more often than Crohn’s disease
  • Look for skin, eye, or joint problems that suggest extra-intestinal IBD
• Nephrolithiasis
  • Intermittent flank pain that waxes and wanes in severity lasting 20 to 60 minutes
  • Sharp pain can localize to anywhere from the flank to the genitals, and may migrate with stone movement
  • May be associated with nausea, dysuria, or urinary urgency
  • Look for gross or microscopic hematuria
• Chronic pancreatitis
  • Episodic epigastric pain that often radiates to the back
  • May be associated with nausea and vomiting
  • May become continuous as the disease progresses
  • Look for evidence of pancreatic insufficiency such as loose, greasy, foul smelling stools that are difficult to flush
• Chronic mesenteric ischemia
  • Recurrent episodes of crampy postprandial epigastric pain within one hour of eating
  • Due to perfusion/demand mismatch in patients with atherosclerosis of the splanchnic circulation
  • Variable intensity and location, and may radiate to the back
  • Look for weight loss from food aversion in anticipation of postprandial pain and history of tobacco use and atherosclerotic vascular disease
  • Half of patients have known peripheral vascular or coronary artery disease
• Referred pelvic pain
  • Variable presentation from indolent discomfort to acute, severe pain
  • Consider UTI, prostatitis, menstruation or menorrhagia, pregnancy (including ectopic pregnancy), ovarian cyst, ovarian torsion, PID, tubo-ovarian abscess, endometritis

Evaluation

• The focused physical exam should include:

• Vital signs, including orthostatics
• Inspection: jaundice, scleral icterus, abdominal distension
• Cardiac exam
• Abdominal exam
  • Inspection: look for distension
  • Auscultation: presence, frequency, and quality of bowel sounds
  • Percussion: tympanitic, involuntary guarding
  • Palpation: should be performed last; distract patient during palpation to get a better exam, palpate the painful area last
    • Is the abdomen soft, full, firm, or rigid?
    • Where is it tender?
    • Is there guarding, either voluntary or involuntary?
    • Are there ascites or masses?
• Consider special tests including Murphy’s sign, the Psoas sign, etc.
• Rectal, pelvic, and testicular exams if appropriate
• Testing should be guided by differential diagnoses:
• Serum studies: CBC w/ differential, complete metabolic panel, and lipase
• Radiographic or interventional studies: Ultrasound (for ovarian or hepatobiliary pathology), CT scan (with IV and, if indicated, oral contrast), CT angiography, MRCP, ERCP, endoscopy, and colonoscopy

References

Cartwright SL, Knudson MP. Evaluation of Acute Abdominal Pain in Adults. Am Fam Physician. 2008;77(7):971-8.

Kami  RA, Nowicki  TA, Courtney  DS, Powers  RD.  Pearls and pitfalls in the emergency department evaluation of abdominal pain.  Emerg Med Clin North Am 2003;21(1):61–72.

Lyon C, Clark DC. Diagnosis of Acute Abdominal Pain in Older Patients. Am Fam Physician 2006;74(9):1537-1544.

Stern S, Cifu A, Altkorn D. (2015). Symptom to diagnosis : an evidence-based guide, third edition. New York :Lange Medical Books / McGraw-Hill, Medical Pub. Division,

Trowbridge RL, Rutkowski NK, Shojania KG. Does this patient have acute cholecystitis? JAMA 2003; 289:80.