Abdominal pain is most commonly associated with gastrointestinal (GI) disorders; however, it may also arise from reproductive, genitourinary (GU), musculoskeletal, or vascular causes, as well as from drug use or toxin ingestion. Occasionally, abdominal pain may indicate life-threatening conditions requiring urgent intervention.

Pathophysiology

Pain originates from the abdominopelvic viscera, the parietal peritoneum, or the capsules of solid organs such as the liver, kidneys, or spleen. It can present as acute or chronic, diffuse or localized. Visceral pain develops gradually and is typically described as a deep, dull, aching sensation, poorly localized to the epigastric, periumbilical, or hypogastric regions. Conversely, somatic (parietal or peritoneal) pain is sharp, intense, well localized, and follows rapidly after the insult. This pain is often exacerbated by movement or coughing.

Pain may also be referred to the abdomen from other anatomical sites sharing common nerve supply. Referred pain is typically sharp and well localized, involving skin or deeper tissues and may be associated with hyperesthesia or hyperalgesia.

Mechanisms of pain

Abdominal pain results from mechanisms including stretching or tension of the gut wall, traction on the peritoneum or mesentery, vigorous intestinal contractions, inflammation, ischemia, or sensory nerve irritation.

Emergency Interventions

In cases of sudden, severe abdominal pain, immediately assess vital signs and palpate pulses distal to the waist. Monitor for signs of hypovolemic shock such as tachycardia and hypotension. Establish intravenous access promptly. Emergency surgical intervention may be indicated if the patient exhibits mottled skin below the waist, a pulsatile epigastric mass, or signs of peritoneal irritation such as rebound tenderness and rigidity.

History and Physical Examination

If no immediate life-threatening signs are present, obtain a detailed history:

• Determine if the patient has experienced similar pain previously.

• Characterize the pain (dull, sharp, stabbing, burning).

• Identify exacerbating or relieving factors.

• Establish whether the pain is constant or intermittent and note onset.

Constant, steady pain suggests organ perforation, ischemia, inflammation, or intra-abdominal hemorrhage. Intermittent, cramping pain often indicates obstruction of a hollow viscus.

For intermittent pain, clarify the duration of typical episodes and their location, including any radiation.

Evaluate effects of movement, coughing, exertion, eating, vomiting, elimination, or walking. Patients may describe the pain as indigestion or gas; prompt detailed description is essential.

Screen for substance abuse and review history of vascular, GI, GU, or reproductive conditions. For female patients, inquire about menstrual history, including last menstrual period, pattern changes, or dyspareunia.

Assess appetite, nausea, vomiting, flatulence, bowel habits (constipation, diarrhea, stool consistency), and last bowel movement. Evaluate urinary symptoms such as frequency, urgency, dysuria, and urine appearance.

Perform a thorough physical examination including:

• Vital signs

• Skin turgor and mucous membrane hydration status

• Inspection of abdomen for distention or visible peristalsis; measure abdominal girth if indicated

• Auscultation of bowel sounds and motility assessment

• Percussion of all abdominal quadrants

• Palpation for masses, rigidity, tenderness, guarding, rebound tenderness

• Costovertebral angle tenderness

Causes of abdominal pain

1. Right Upper Quadrant (RUQ)

Main Organs: Liver, gallbladder, duodenum, head of pancreas, right kidney, hepatic flexure of colon.

2. Left upper quadrant (LUQ)

Main Organs: Stomach, spleen, pancreas (body and tail), left kidney, splenic flexure of colon.

3. Epigastric pain

Main Organs: Stomach, duodenum, pancreas, liver, transverse colon.

4. Right lower quadrant (RLQ)

Main Organs: Appendix, terminal ileum, cecum, right ovary/fallopian tube, right ureter.

5. Left lower quadrant (LLQ)

Main Organs: Sigmoid colon, left ovary/fallopian tube, left ureter.

6. Periumbilical

7. Suprapubic

Special Considerations

Assist the patient in finding a comfortable position to minimize discomfort, typically supine with head flat, arms at sides, and knees slightly flexed to relax abdominal musculature. Monitor closely for deterioration, including tachycardia, hypotension, diaphoresis, abdominal rigidity, rebound tenderness, or changes in pain character. Sudden relief may paradoxically indicate perforation.

Avoid analgesics as they may obscure clinical findings. Withhold oral intake in anticipation of potential surgical intervention. Prepare for intravenous fluid therapy and possible insertion of a nasogastric or intestinal tube. Diagnostic procedures such as peritoneal lavage or abdominal paracentesis may be required.

Prepare for diagnostic evaluations including pelvic and rectal examinations, laboratory tests (blood, urine, stool), imaging (X-rays, barium studies, ultrasonography), endoscopy, and biopsy.

Patient Counseling

Inform patients about the rationale for diagnostic tests and the necessity of withholding specific foods and fluids. Emphasize the importance of reporting any changes in bowel habits or pain characteristics. Educate on proper positioning techniques to alleviate symptoms.

Pediatric Considerations

Children often have difficulty articulating abdominal pain; therefore, observe for nonverbal cues such as wincing, lethargy, or protective positioning (e.g., sidelying with knees flexed). Observation during movement (coughing, walking, climbing) may provide additional diagnostic clues. Parental descriptions may be subjective and should be interpreted cautiously.

Abdominal pain in pediatric patients can signify more severe pathology or present with atypical signs compared to adults. For example, appendicitis has a higher risk of rupture and mortality in children, with vomiting sometimes the only associated symptom. Acute pyelonephritis may present with abdominal pain, vomiting, and diarrhea but lack classic adult urologic signs. Peptic ulcer disease, increasingly seen in adolescents, often causes nocturnal pain and colic not relieved by food intake, unlike in adults.

Other pediatric causes include lactose intolerance, allergic-tension-fatigue syndrome, volvulus, Meckel’s diverticulum, intussusception, mesenteric adenitis, diabetes mellitus, juvenile rheumatoid arthritis, and rare conditions like heavy metal poisoning. Emotional or psychosocial factors should also be considered.

Geriatric Considerations

Older adults may exhibit diminished clinical manifestations of acute abdominal pathology. Pain intensity may be reduced, fever less pronounced, and signs of peritoneal irritation may be subtle or absent.

References

1. McCutcheon, T. (2013). The ileus and oddities after colorectal surgery. Gastroenterology Nursing, 36(5), 368–375.

2. Saccamano, S., & Ferrara, L. (2013). Evaluation of acute abdominal pain. The Nurse Practitioner: The American Journal of Primary Health Care, 38(11), 46–53.

3. Long B, Koyfman A, Gottlieb M. Emergency department evaluation and management of acute abdominal pain. Emerg Med Clin North Am. 2018;36(3):549-567. doi:10.1016/j.emc.2018.03.009

4. Ritchie C, Dunne C, McAlpine R. Approach to acute abdominal pain. BMJ. 2021;374:n1588. doi:10.1136/bmj.n1588

5. Lameris W, van Randen A, van Es HW, et al. Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study. BMJ. 2009;339:b2431. doi:10.1136/bmj.b2431

6. Broder J, Fordham LA, Chang Y, et al. Diagnosing acute appendicitis: a systematic review and meta-analysis of diagnostic accuracy of clinical signs and symptoms. Ann Emerg Med. 2012;60(2):226-234. doi:10.1016/j.annemergmed.2012.01.023

7. Stulberg J, Jaffe TA, Rosenthal R. Acute abdominal pain in older adults: evaluation and management. Am Fam Physician. 2014;90(9):625-633.

8. Roberts JR, Hedges JR. Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia: Elsevier Saunders; 2014. Chapter 15, Abdominal pain and related procedures.

9. Kottke-Marchant K, Davis KA. Approach to the patient with abdominal pain. In: Goldman L, Schafer AI, editors. Goldman-Cecil Medicine. 25th ed. Philadelphia: Elsevier; 2016. p. 1602-1608.

10. Henry MC, Sullivan EA, Wernecke M, et al. Role of diagnostic laparoscopy in acute abdominal pain. Surg Endosc. 2015;29(10):3103-3110. doi:10.1007/s00464-015-4181-7

11. Jeon HJ, Lee YH, Choi GS. Acute abdomen: imaging strategy in the emergency department. World J Gastroenterol. 2016;22(6):1833-1843. doi:10.3748/wjg.v22.i6.1833

12. Pauls LA, Thorlund K, Walter SD, et al. Diagnostic accuracy of blood tests for appendicitis in children: a systematic review and meta-analysis. J Pediatr Surg. 2020;55(10):2146-2154. doi:10.1016/j.jpedsurg.2020.06.022