Acute Abdomen by region

D/D acute abdomen by region: RUQ

• Hepatobiliary: Biliary colic, Cholecystitis, Cholangitis, CBD obstruction (stone, tumor), Hepatitis, Budd-Chiari, Hepatic abscess/mass, Right subphrenic abscess.

• Gastrointestinal: Pancreatitis, Presentation of gastric, duodenal, or pancreatic pathology, Hepatic flexure pathology (CRC, subcostal incisional hernia).

• Genitourinary: Nephrolithiasis, Pyelonephritis, Renal: mass, ischemia, trauma.

• Cardiopulmonary: RLL pneumonia, Effusion/empyema, CHF (causing hepatic congestion and R pleural effusion),MI, Pericarditis, Pleuritis

• Miscellaneous: Herpes zoster, Trauma, Costochondritis

D/D acute abdomen by region: LUQ

• Pancreatic: Pancreatitis (acute vs. chronic), Pancreatic pseudocyst, Pancreatic tumors.

• Gastrointestinal: Gastritis, PUD, Splenic flexure pathology, (e.g. CRC, ischemia).

• Splenic: Splenic infarct/abscess, Splenomegaly, Splenic rupture, Splenic artery aneurysm.

• Cardiopulmonary (see RUQ and Epigastric).

• Genitourinary (see RUQ).

D/D acute abdomen by region: RLQ

• Gastrointestinal: Appendicitis, Crohn’s disease, Tuberculosis of the ileocecal junction, Cecal tumor, Intussusception, Mesenteric lymphadenitis (Yersinia), Cecal diverticulitis, Cecal volvulus.
• Hernia: femoral, inguinal obstruction, Amyand’s (and resulting cecal distention)
• Gynecological: See ‘suprapubic’
• Genitourinary: See ‘suprapubic’
• Extraperitoneal: Abdominal wall hematoma/abscess, Psoas abscess

D/D acute abdomen by region: LLQ

• Gastrointestinal: Diverticulitis, Diverticulosis, Colon/sigmoid/rectal cancer, Fecal impaction, Proctitis (ulcerative colitis, infectious ; i.e. gonococcus or Chlamydia), Sigmoid volvulus
• Hernia
• Gynecological: See ‘suprapubic’
• Genitourinary: See ‘suprapubic’
• Extraperitoneal: Abdominal wall hematoma/abscess, Psoas abscess

D/D acute abdomen by region: Epigastric

• Cardiac: Aortic dissection/ruptured, AAA, MI, Pericarditis
• Gastrointestinal: Gastritis, GERD/esophagitis, PUD, Pancreatitis, Mallory-Weiss tear.

D/D acute abdomen by region: Suprapubic

• Gastrointestinal (see RLQ/LLQ): Acute appendicitis, IBD,
• Gynecological: Ectopic pregnancy, PID, Endometriosis ,Threatened/incomplete, abortion, Hydrosalpinx/salpingitis, Ovarian torsion, Hemorrhagic fibroid, Tubo-ovarian abscess, Gynecological tumors
• Genitourinary, Cystitis (infectious, hemorrhagic), Hydroureter/urinary colic, Epididymitis, Testicular torsion, acute urinary retention
• Extraperitoneal: Rectus sheath hematoma

D/D acute abdomen by region: Diffuse

• Gastrointestinal: Peritonitis, Early appendicitis, perforated appendicitis, Mesenteric ischemia, Gastroenteritis/colitis, Constipation, Bowel obstruction, Pancreatitis, Inflammatory bowel disease, Irritable bowel syndrome, Ogilvie’s syndrome
• Cardiovascular/Hematological: Aortic dissection/ruptured AAA, Sickle cell crisis
• Genitourinary/Gynecological: Perforated ectopic pregnancy, PID, Acute urinary retention
• Endocrinological: Carcinoid syndrome, Diabetic ketoacidosis, Addisonian crisis, Hypercalcemia
• Others: Lead poisoning, Tertiary syphilis

Region	Category	Differential Diagnosis
RUQ	Hepatobiliary	Biliary colic, Cholecystitis, Cholangitis, CBD obstruction (stone, tumor), Hepatitis, Budd-Chiari, Hepatic abscess/mass, Right subphrenic abscess
	Gastrointestinal	Pancreatitis, Presentation of gastric, duodenal, or pancreatic pathology, Hepatic flexure pathology (CRC, subcostal incisional hernia)
	Genitourinary	Nephrolithiasis, Pyelonephritis, Renal: mass, ischemia, trauma
	Cardiopulmonary	RLL pneumonia, Effusion/empyema, CHF (causing hepatic congestion and R pleural effusion), MI, Pericarditis, Pleuritis
	Miscellaneous	Herpes zoster, Trauma, Costochondritis
LUQ	Pancreatic	Pancreatitis (acute vs. chronic), Pancreatic pseudocyst, Pancreatic tumors
	Gastrointestinal	Gastritis, PUD, Splenic flexure pathology (e.g. CRC, ischemia)
	Splenic	Splenic infarct/abscess, Splenomegaly, Splenic rupture, Splenic artery aneurysm
	Cardiopulmonary	(see RUQ and Epigastric)
	Genitourinary	(see RUQ)
RLQ	Gastrointestinal	Appendicitis, Crohn’s disease, Tuberculosis of the ileocecal junction, Cecal tumor, Intussusception, Mesenteric lymphadenitis (Yersinia), Cecal diverticulitis, Cecal volvulus
	Hernia	Femoral, inguinal obstruction, Amyand’s (and resulting cecal distention)
	Gynecological	See ‘suprapubic’
	Genitourinary	See ‘suprapubic’
	Extraperitoneal	Abdominal wall hematoma/abscess, Psoas abscess
LLQ	Gastrointestinal	Diverticulitis, Diverticulosis, Colon/sigmoid/rectal cancer, Fecal impaction, Proctitis (ulcerative colitis, infectious; i.e. gonococcus or Chlamydia), Sigmoid volvulus
	Hernia
	Gynecological	See ‘suprapubic’
	Genitourinary	See ‘suprapubic’
	Extraperitoneal	Abdominal wall hematoma/abscess, Psoas abscess
Epigastric	Cardiac	Aortic dissection/ruptured, AAA, MI, Pericarditis
	Gastrointestinal	Gastritis, GERD/esophagitis, PUD, Pancreatitis, Mallory-Weiss tear
Suprapubic	Gastrointestinal	(see RLQ/LLQ): Acute appendicitis, IBD
	Gynecological	Ectopic pregnancy, PID, Endometriosis, Threatened/incomplete abortion, Hydrosalpinx/salpingitis, Ovarian torsion, Hemorrhagic fibroid, Tubo-ovarian abscess, Gynecological tumors
	Genitourinary	Cystitis (infectious, hemorrhagic), Hydroureter/urinary colic, Epididymitis, Testicular torsion, acute urinary retention
	Extraperitoneal	Rectus sheath hematoma
Diffuse	Gastrointestinal	Peritonitis, Early appendicitis, perforated appendicitis, Mesenteric ischemia, Gastroenteritis/colitis, Constipation, Bowel obstruction, Pancreatitis, Inflammatory bowel disease, Irritable bowel syndrome, Ogilvie’s syndrome
	Cardiovascular/Hematological	Aortic dissection/ruptured AAA, Sickle cell crisis
	Genitourinary/Gynecological	Perforated ectopic pregnancy, PID, Acute urinary retention
	Endocrinological	Carcinoid syndrome, Diabetic ketoacidosis, Addisonian crisis, Hypercalcemia
	Others	Lead poisoning, Tertiary syphilis