Abdominal Pain (Stomach Ache)

Abdominal pain (or stomach ache) can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem. Most frequently the cause is benign and/or self-limited, but more serious causes may require urgent intervention.

Causes

The following is an incomplete list of possible causes of abdominal pain.

• Gastrointestinal
  • Inflammatory: gastroenteritis, appendicitis, gastritis, esophagitis, diverticulitis, Crohn’s disease, ulcerative colitis, microscopic colitis
  • Obstruction: hernia, intussusception, volvulus, post-surgical adhesions, tumours, superior mesenteric artery syndrome, severe constipation, hemorrhoids
  • Vascular: embolism, thrombosis, hemorrhage, sickle cell disease, abdominal angina, blood vessel compression (such as celiac artery compression syndrome)
  • digestive: peptic ulcer, lactose intolerance, celiac sprue (affecting 1:133 people), food allergies, Jasohnstritis
• Bile system
  • Inflammatory: cholecystitis, cholangitis
  • Obstruction: cholelithiasis, tumours
• Liver
  • Inflammatory: hepatitis, liver abscess
• Pancreatic
  • Inflammatory: pancreatitis
• Renal and urological
  • Inflammation: pyelonephritis, bladder infection
  • Obstruction: kidney stones, urolithiasis, Urinary retention, tumours
  • Vascular: left renal vein entrapment
• Gynecological or obstetric
  • Inflammatory: pelvic inflammatory disease
  • Mechanical: ovarian torsion
  • Endocrinological: menstruation, Mittelschmerz
  • Tumors: endometriosis, fibroids, ovarian cyst, ovarian cancer
  • Pregnancy: ruptured ectopic pregnancy, threatened abortion
• Abdominal wall
  • muscle strain or trauma
  • muscular infection
  • neurogenic pain: herpes zoster, radiculitis in Lyme disease, abdominal cutaneous nerve entrapment syndrome (ACNES), tabes dorsalis
• Referred pain
  • from the thorax: pneumonia, pulmonary embolism, ischemic heart disease, pericarditis
  • from the spine: radiculitis
  • from the genitals: testicular torsion
• Metabolic disturbance
  • uremia, diabetic ketoacidosis, porphyria, C1-esterase inhibitor deficiency, adrenal insufficiency, lead poisoning, black widow spider bite, narcotic withdrawal
• Blood vessels
  • aortic dissection, abdominal aortic aneurysm
• Immune system
  • sarcoidosis
  • vasculitis
  • familial Mediterranean fever
• Idiopathic
  • irritable bowel syndrome (affecting up to 20% of the population, IBS is the most common cause of recurrent, intermittent abdominal pain)

Medical Assessment

When a physician assesses a patient to determine the etiology and subsequent treatment for abdominal pain the patients history of the presenting complaint and physical examination should derive a diagnosis in over 90% of cases.

It is important also for a physician to remember that abdominal pain can be caused by problems outside the abdomen, especially heart attacks and pneumonias which can occasionally present as abdominal pain.

Investigations that would aid diagnosis include

• Blood tests including full blood count, electrolytes, urea, creatinine, liver function tests, pregnancy test and lipase.
• Urinalysis
• Imaging including erect chest X-ray and plain films of the abdomen
• An electrocardiograph to rule out a heart attack which can occasionally present as abdominal pain

If diagnosis remains unclear after history, examination and basic investigations as above then more advanced investigations may reveal a diagnosis. These as such would include

• Computed Tomography of the abdomen/pelvis
• Abdominal or pelvic ultrasound
• Endoscopy and colonoscopy (not used for diagnosing acute pain)