DDx – Abdominal Pain
Source: Churchill’s Pocketbook of Differential Diagnosis
Bold: common; Italic: rare
GASTROINTESTINAL
- Peptic ulcer
- Gastritis
- Malignancy
- Gastric volvulus
- Appendicitis
- Obstruction
- Diverticulitis
- Gastroenteritis
- Mesenteric adenitis
- Strangulated hernia
- Inflammatory bowel disease
- Intussusception
- Volvulus
- TB (common in parts of the world where TB is endemic)
HEPATOBILIARY
- Acute cholecystitis
- Chronic cholecystitis
- Cholangitis
- Hepatitis
PANCREATIC
- Acute pancreatitis
- Chronic pancreatitis
- Malignancy
SPLENIC
- Infarction
- Spontaneous rupture
URINARY TRACT
- Cystitis
- Acute retention of urine
- Acute pyelonephritis
- Ureteric colic
- Hydronephrosis
- Tumour
- Pyonephrosis
- Polycystic kidney
GYNAECOLOGICAL
- Ruptured ectopic pregnancy
- Torsion of ovarian cyst
- Ruptured ovarian cyst
- Salpingitis
- Severe dysmenorrhoea
- Mittelschmerz
- Endometriosis
- Red degeneration of a fibroid
VASCULAR
- Aortic aneurysm
- Mesenteric embolus
- Mesenteric angina (claudication)
- Mesenteric venous thrombosis
- Ischaemic colitis
- Acute aortic dissection
PERITONEUM
- Secondary peritonitis
- Primary peritonitis
ABDOMINAL WALL
- Strangulated hernia
- Rectus sheath haematoma
- Cellulitis
RETROPERITONEUM
- Retroperitoneal haemorrhage,e.g. anticoagulants
REFERRED PAIN
- Myocardial infarction
- Pericarditis
- Testicular torsion
- Pleurisy
- Herpes zoster
- Lobar pneumonia
- Thoracic spine disease, e.g. disc, tumour
‘MEDICAL’ CAUSES
- Hypercalcaemia
- Uraemia
- Diabetic ketoacidosis
- Sickle cell disease
- Addison’s disease
- Acute intermittent porphyria
- Henoch–Schönlein purpura
- Tabes dorsalis
GENERAL INVESTIGATIONS
■ FBC, ESR
Hb peptic ulcer disease, malignancy. WCC infective/ inflammatory disease, e.g. appendicitis, diverticulitis. ESR Crohn’s disease, TB.
■ U&Es
Urea and creatinine uraemia. Electrolyte disturbances in vomiting and diarrhoea.
■ LFTs
Abnormal in cholangitis and hepatitis. Often abnormal in acute cholecystitis.
■ Serum amylase
Markedly raised in acute pancreatitis. Often moderately raised with perforated peptic ulcer or infarcted bowel.
■ MSU
Blood, protein, culture positive in pyelonephritis. Red cells in ureteric colic.
■ CXR
Gas under diaphragm (perforated viscus). Lower lobar pneumonia (referred pain).
■ AXR
Obstruction – dilated loops of bowel. Site of obstruction. Local ileus (sentinel loop) – pancreatitis, acute appendicitis. Toxic dilatation – dilated, featureless, oedematous colon in ulcerative colitis or Crohn’s disease. Renal calculi. Calcified aortic aneurysm. Air in biliary tree (gallstone ileus). Gallstones (10% radio-opaque).
■ US
Localised abscesses, e.g. appendix abscess, paracolic abscess in diverticular disease. Free fluid – peritonitis, ascites. Aortic aneurysm. Ectopic pregnancy. Ovarian cyst. Gallstones.
Empyema, mucocele of gall bladder. Kidney – cysts, tumour.
SPECIFIC INVESTIGATIONS
Blood glucose
Raised in diabetic ketoacidosis.
■ Serum calcium
Hypercalcaemia.
■ CRP
Crohn’s disease.
■ VDRL
Syphilis (tabes dorsalis).
■ Sickling test
Sickle cell disease.
■ Urinary porphobilinogens
Acute intermittent porphyria.
■ ABGs
Metabolic acidosis, e.g. uraemia, infarcted bowel, sepsis, diabetic ketoacidosis.
■ bHCG
Pregnancy. Ectopic pregnancy.
■ ECG
Myocardial infarction (referred pain).
■ OGD
Peptic ulcer. Malignancy.
■ IVU
Stones. Obstruction.
■ Barium enema
Carcinoma. Volvulus. Intussusception.
■ Small bowel enema
Small bowel Crohn’s disease. Lymphoma of small bowel. Carcinoma of small bowel.
■ Duplex Doppler
Superior mesenteric artery stenosis (mesenteric angina). Superior mesenteric artery thrombosis. Mesenteric venous thrombosis.
■ Angiography
Superior mesenteric embolus or thrombosis.
■ CT
Aneurysm. Pancreatitis. Tumour.
■ MRCP
Biliary tract disease.