Why Abdominal Pain Matters
Abdominal pain is one of the most common reasons for outpatient visits and emergency admissions. Its causes range from benign to life-threatening emergencies like perforation or malignancy.
Clinicians must systematically approach every case using structured tools like mnemonics. One such lifesaving tool is the ABDOMINAL mnemonic.
What is Differential Diagnosis in Abdominal Pain?
Differential diagnosis involves listing possible conditions that could explain the patient's symptoms, then ruling them out systematically based on:
- Location of pain
- Quality and timing
- Associated symptoms (fever, vomiting, bleeding, etc.)
- Lab and imaging results
Mnemonic ABDOMINAL Overview
| Letter | Condition |
|---|---|
| A | Appendicitis |
| B | Biliary tract disease |
| D | Diverticulitis |
| O | Ovarian disease |
| M | Malignancy |
| I | Intestinal obstruction |
| N | Nephritic disorders |
| A | Acute pancreatitis |
| L | Liquor (alcohol-related) |
A – Appendicitis
- Common cause of right lower quadrant pain
- Classic signs: McBurney's point tenderness, fever, leukocytosis
- Seen in young adults and children
CT abdomen and ultrasound are diagnostic tools.
B – Biliary Tract Disease
Includes:
- Cholelithiasis (gallstones)
- Cholecystitis
- Choledocholithiasis
- Cholangitis
Signs: RUQ pain, fever, jaundice (Charcot’s triad), Murphy’s sign
D – Diverticulitis
- Common in the elderly
- Usually left lower quadrant pain
- May present with fever, constipation, tenderness
CT scan helps confirm diagnosis. Avoid colonoscopy during acute phase.
O – Ovarian Disorders
| Disorder | Symptoms |
|---|---|
| Ovarian cyst rupture | Sudden unilateral pain |
| Ovarian torsion | Acute pelvic pain + vomiting |
| Ectopic pregnancy | Missed period + pain + bleeding |
Pelvic ultrasound is essential for diagnosis.
M – Malignancy
- Can mimic benign causes
- Colorectal, pancreatic, ovarian cancers often present late
- Look for: Weight loss, GI bleeding, night sweats, early satiety
Red flags should trigger colonoscopy or CT scan.
I – Intestinal Obstruction
- Sudden onset pain with distension, vomiting, constipation
- High-pitched bowel sounds or silence
- Common causes: adhesions, hernia, tumors
X-ray shows dilated loops + air-fluid levels.
N – Nephritic Disorders
Includes:
- Kidney stones (renal colic) – Flank pain radiating to groin
- Pyelonephritis – Fever, back pain, dysuria
- Glomerulonephritis – Hematuria, hypertension, edema
Urinalysis and CT KUB are key investigations.
A – Acute Pancreatitis
- Severe epigastric pain, radiating to back
- Nausea, vomiting, elevated serum lipase/amylase
- Common triggers: Alcohol, gallstones, hypertriglyceridemia
CT scan or USG if diagnosis unclear.
L – Liquor (Ethanol-Induced Abdominal Pain)
Chronic alcohol use can cause:
- Gastritis
- Pancreatitis
- Liver disease
History is crucial. Always screen for alcohol abuse.
How to Use the Mnemonic in Clinical Practice
Whenever a patient presents with abdominal pain:
- Run through each letter in your mind
- Use history + physical exam + focused labs to rule in or out
- Helps avoid misdiagnosis and speeds up emergency decision-making
Red Flag Symptoms in Abdominal Pain
- Hematemesis / melena
- Unexplained weight loss
- Fever + guarding
- Hypotension or shock
- Altered mental status
These warrant urgent referral and imaging.
Age and Gender-Specific Considerations
| Group | Common Causes |
|---|---|
| Children | Appendicitis, mesenteric adenitis |
| Elderly | Diverticulitis, malignancy |
| Women (repro age) | Ovarian torsion, ectopic pregnancy |
History and Physical Exam Clues
- Onset: Sudden or gradual?
- Location: RLQ (appendix), LUQ (gastric), Epigastric (pancreas)
- Relief with position change: Suggests peritonitis or obstruction
- Associated symptoms: Vomiting, diarrhea, urinary changes
Don’t forget rectal and pelvic exams where indicated.
Common Investigations and Labs
- CBC, CRP, ESR
- LFT, RFT, Lipase/Amylase
- Urinalysis
- Beta-hCG (for all women of reproductive age)
- Ultrasound, CT, or MRI as required
When to Refer to Surgery or Emergency
Immediate surgical referral if:
- Signs of peritonitis
- Suspected bowel obstruction or perforation
- Ruptured ectopic pregnancy
- Pancreatitis with hemodynamic instability
ABDOMINAL Mnemonic Recap Table
| Letter | Diagnosis | Clue/Location |
|---|---|---|
| A | Appendicitis | RLQ, rebound tenderness |
| B | Biliary disease | RUQ, fever, Murphy’s sign |
| D | Diverticulitis | LLQ, elderly |
| O | Ovarian disorders | Pelvic, reproductive age female |
| M | Malignancy | Weight loss, altered bowel habit |
| I | Intestinal obstruction | Vomiting, no flatus |
| N | Nephritic disorders | Flank pain, hematuria |
| A | Acute pancreatitis | Epigastric pain, alcohol history |
| L | Liquor-related | Vague, chronic epigastric pain |
Final Thoughts and Clinical Pearls
- Always think broadly first, then narrow down.
- The ABDOMINAL mnemonic ensures you don’t miss uncommon or overlapping conditions.
- Use it for emergency triage, OSCE prep, and clinical rounds.
- Trust the basics—history and physical exam remain key.
FAQs on Abdominal Pain Diagnosis
Q1. What’s the most common cause of abdominal pain in the ER?
Appendicitis and gastroenteritis top the list.
Q2. Should I always get a CT scan?
No—start with labs and ultrasound; CT is for complicated cases.
Q3. Can acid reflux cause severe abdominal pain?
Yes, GERD can mimic cardiac or gastric causes.
🧠Related Medical Topics You Shouldn't Miss:
- Atherosclerosis and Risk Factors
- Peptic Ulcer Symptoms (FAB-TIME)
- Trigeminal Neuralgia Nursing Care
- Drugs That Cause Gout (CANDLE-CAP)
- ECG Changes in Electrolyte Imbalance
- Hypernatremia Symptoms (FRIED)
- Status Epilepticus Complications (HARRAS)
- Mumps Clinical Features (SOAP)
- Arsenic Poisoning Signs (HARMFul CASH)
- Hypoxia Early Signs (RAT Mnemonic)
- Mercury Poisoning (SMELL & BLACK TEA)
- Myasthenia Gravis (Features + Drug Mnemonic)
- Jaundice and Cholestasis Symptoms
- Hepatitis Treatment (HEPATITIS Mnemonic)
