What is the appropriate evaluation and management for an adult patient presenting with stomach ache?

Evaluation and Management of Stomach Ache in Adults

For adults presenting with stomach ache, begin with rapid assessment of vital signs and alarm features to identify life-threatening conditions, then use pain location to guide imaging: CT abdomen/pelvis with contrast for non-localized or lower quadrant pain, and ultrasound for right upper quadrant pain. 1, 2, 3

Immediate Red Flag Assessment

Evaluate for critical conditions requiring urgent intervention:

• Hemodynamic instability (tachycardia, hypotension, tachypnea) indicates bleeding or sepsis and requires immediate resuscitation 2, 3
• Severe pain out of proportion to physical examination suggests mesenteric ischemia until proven otherwise and warrants immediate surgical consultation 2, 3
• Sudden onset pain with hypotension indicates possible ruptured abdominal aortic aneurysm (mortality >50%) 2
• Peritoneal signs (abdominal rigidity, rebound tenderness) require urgent evaluation for perforation or ischemia 2, 3
• Abdominal distension with vomiting suggests intestinal obstruction 2, 3
• Fever with severe abdominal pain indicates infection, abscess, or perforation 2, 3

Tachycardia is the most sensitive early warning sign of surgical complications and should trigger urgent investigation even before other symptoms develop. 3

Focused History Elements

Obtain specific details that narrow the differential:

• Pain characteristics: Abrupt onset suggests vascular catastrophe (aortic dissection, mesenteric ischemia); colicky pain indicates bowel obstruction 3
• Last bowel movement and gas passage: 85% sensitivity and 78% specificity for adhesive small bowel obstruction in patients with prior abdominal surgery 3
• Associated symptoms: Vomiting occurs earlier in small bowel versus large bowel obstruction; occult blood in stool occurs in 25% of mesenteric ischemia cases 3
• Past surgical history: Any prior laparotomy makes adhesive obstruction the leading diagnosis (55-75% of small bowel obstructions) 3
• Cardiovascular disease history: Atrial fibrillation present in nearly 50% of embolic mesenteric ischemia; recent myocardial infarction predisposes to mesenteric arterial thrombosis 3
• Medications: Oral contraceptives/estrogen predispose to mesenteric venous thrombosis; vasoconstrictive agents may precipitate non-occlusive mesenteric ischemia; psychotropic medications cause chronic constipation predisposing to volvulus 3

Physical Examination Priorities

• Vital signs: Fever, tachycardia (>100 bpm), hypotension, or tachypnea indicate infection, bleeding, or sepsis 2, 3
• Abdominal examination: Check for peritoneal signs, distension, Murphy's sign (right upper quadrant tenderness suggesting cholecystitis) 3
• Hernia orifices and surgical scars: Failure to examine these can miss incarcerated hernias 4
• Rectal examination: Empty rectum is classic for sigmoid volvulus 3

Note that classic peritoneal signs are often absent in certain populations (post-bariatric surgery patients, elderly with chronic conditions), and absence of peritonitis does not exclude bowel ischemia. 3

Laboratory Testing

Order the following based on clinical suspicion:

• Complete blood count: Evaluate for leukocytosis indicating infection or inflammation 3
• C-reactive protein: Higher sensitivity and specificity than white blood cell count for confirming surgical disease 2, 3
• Lactate: Elevated levels suggest ischemia or sepsis, though normal levels do not exclude early ischemia 2, 3
• Metabolic panel, liver function tests, amylase, lipase: Evaluate for metabolic disorders, liver disease, and pancreatitis 2, 3
• β-hCG in all women of reproductive age before imaging: Failure to obtain this test can delay diagnosis of ectopic pregnancy 3, 4
• Procalcitonin: Helpful for assessing inflammatory response in suspected sepsis 3

Common pitfall: Do not over-rely on normal laboratory values early in disease—many tests are nonspecific and may be normal despite serious infection, especially in elderly patients. 3, 4

Imaging Strategy by Pain Location

Right Upper Quadrant Pain

• Ultrasound is the initial imaging test of choice for suspected cholecystitis (sensitivity 81%, specificity 83%) 1, 3
• Ultrasound identifies other potential causes of pain and avoids ionizing radiation 1
• Consider CT if ultrasound is inconclusive or to guide surgical planning 1

Right Lower Quadrant Pain

• CT abdomen/pelvis with contrast is the most appropriate initial imaging for suspected appendicitis (sensitivity 97%, specificity 94%) 1, 3
• Ultrasound can be considered first in select cases: when definitive results are obtained, sensitivity is 99% and specificity is 95%, but including equivocal results drops sensitivity to 68% 1
• Always consider ectopic pregnancy in women of reproductive age 3, 4

Left Lower Quadrant Pain

• CT abdomen/pelvis with contrast is recommended for suspected diverticulitis (sensitivity >95%) 1, 3
• CT provides information about disease extent and abscess formation 1

Non-Localized or Diffuse Abdominal Pain

• CT abdomen/pelvis with contrast is the imaging modality of choice, changing the primary diagnosis in 49-51% of patients and altering management in 42% of cases 1, 2, 3
• CT provides comprehensive evaluation of all abdominal organs in a single examination 2
• CT angiography is the gold standard for diagnosing mesenteric ischemia and aortic pathology 2

Conventional radiography has limited diagnostic value in most patients with abdominal pain and should not be routinely ordered. 1, 3 It may be appropriate only for suspected bowel obstruction, perforated viscus, urinary calculi, or foreign bodies 1

Special Population Considerations

Elderly Patients

• Symptoms may be atypical with normal laboratory tests 1, 3, 4
• Higher likelihood of malignancy, diverticulitis, and vascular causes 3, 4
• Consider endoscopy in older patients with suboptimal response to treatment 5

Women of Reproductive Age

• Always obtain β-hCG before imaging 3, 4
• Consider gynecologic conditions: ectopic pregnancy, ovarian torsion, pelvic inflammatory disease 3
• Use ultrasound and MRI (not CT) in pregnant women to avoid radiation exposure 2

Post-Bariatric Surgery Patients

• Often present with atypical symptoms 2, 3
• Tachycardia is the most critical warning sign 2, 3
• Classic peritoneal signs often absent; consider internal herniation even with normal lactate 3

Immunocompromised Patients

• May have masked signs of abdominal sepsis with delayed diagnosis and high mortality 3

Management Approach by Diagnosis

Suspected Appendicitis

• CT sensitivity 97%, specificity 94% in adults 1
• Surgical consultation for definitive management 1

Suspected Cholecystitis

• Ultrasound is first-line imaging 1, 3
• Surgical consultation for cholecystectomy 1

Suspected Diverticulitis

• CT sensitivity >95% 1
• Outpatient management with antibiotics for uncomplicated cases; surgical consultation if abscess, perforation, or obstruction 1

Suspected Bowel Obstruction

• CT abdomen/pelvis with contrast 3
• Adhesions account for 55-75% of small bowel obstructions; hernias cause 15-25% 4
• Surgical consultation for management 3

Suspected Mesenteric Ischemia

• CT angiography immediately 2
• Immediate surgical consultation (mortality 30-90%) 2

Functional Disorders

• Consider after organic pathology confidently excluded 6
• Once functional pain is established, repetitive testing is not recommended 6
• Refer for psychological support (cognitive therapy) with pharmacological options 6

Peptic Ulcer Disease/GERD

• If diagnosed, omeprazole 20 mg once daily before meals for symptomatic GERD (up to 4 weeks) or 20-40 mg once daily for peptic ulcer disease (4-8 weeks) 5
• Symptomatic response does not preclude gastric malignancy in adults; consider endoscopy in older patients or those with suboptimal response 5

Critical Pitfalls to Avoid

• Do not dismiss tachycardia as an early warning sign even before other symptoms develop 2, 3
• Do not assume negative ultrasound rules out severe pathology—proceed to CT if clinical suspicion persists 2
• Do not delay CT in patients with clinical deterioration while performing additional non-diagnostic tests 2
• Do not forget pregnancy testing in women of reproductive age before CT 2, 3, 4
• Do not overlook hernia orifices and surgical scars during examination 4
• Do not over-rely on normal laboratory values early in disease, especially in elderly patients 3, 4
• Do not routinely order plain radiographs as they have limited diagnostic value 1, 3