What could be causing right-sided abdominal pain below the ribs that worsens with physical stress in a young adult?

Right-Sided Abdominal Pain Below Ribs with Physical Stress in a 21-Year-Old Male

Most Likely Diagnosis

This presentation is most consistent with exercise-induced gastrointestinal symptoms, particularly related to constipation or irritable bowel syndrome, though cardiac and other serious causes must be systematically excluded first. 1

Immediate Evaluation Required

Before attributing this pain to benign gastrointestinal causes, you must exclude life-threatening conditions:

Cardiac Evaluation

• Obtain an ECG immediately to rule out cardiac ischemia, even in this young patient 2
• Anginal symptoms can present atypically in young adults, though pain radiating below the umbilicus or localized to a very limited area is unlikely to be cardiac 2
• Sharp pain that increases with inspiration is unlikely related to ischemic heart disease 2
• If the pain is positional or musculoskeletal in nature, cardiac causes are less likely 2

Other Serious Causes to Exclude

• Mesenteric ischemia: Right-sided abdominal pain associated with physical stress in the context of critical illness or vasopressor use should raise concern, though this is uncommon in healthy young adults 2
• Pulmonary embolism: Assess for dyspnea, tachycardia, and pain with inspiration 2, 1
• Pneumothorax: Look for dyspnea and unilateral absence of breath sounds 2

Most Probable Gastrointestinal Causes

Constipation-Related Pain

Severe constipation can cause right-sided abdominal pain that worsens with physical activity, accounting for approximately 10-20% of chest and upper abdominal pain cases 1:

• Evaluate bowel habits including frequency, straining, and incomplete evacuation 1
• Perform abdominal examination for distention and tenderness 1
• Consider digital rectal examination to assess for fecal impaction 1
• Chronic constipation is common and must be aggressively treated with osmotic laxatives and increased water/fiber intake 2

Irritable Bowel Syndrome

Right-sided abdominal pain with physical stress may represent IBS, particularly if associated with altered bowel habits 2:

• Rome II criteria: At least 12 weeks of abdominal discomfort relieved with defecation, associated with change in stool frequency or form 2
• Physical stress can exacerbate symptoms through brain-gut axis dysregulation 2
• Symptoms of bloating, flatulence, and altered transit correlate with physical findings 2

Other Gastrointestinal Considerations

• Gallbladder disease: Assess for right upper quadrant tenderness and Murphy sign 2
• Diverticular disease: Can occur in young adults with Williams syndrome or other predisposing conditions, though rare at age 21 2
• Gastroesophageal reflux or hiatal hernia: May present as upper abdominal pain 2

Diagnostic Approach

History Details to Obtain

• Temporal pattern: Does pain occur during exercise, immediately after, or hours later? 2
• Bowel habits: Frequency, consistency, straining, incomplete evacuation 1
• Associated symptoms: Nausea, vomiting, changes in stool, dyspnea, diaphoresis 2
• Dietary triggers: Relationship to meals, specific foods 2
• Psychological stress: IBS symptoms worsen with stress 2

Physical Examination Priorities

• Vital signs including oxygen saturation 2
• Cardiac auscultation and peripheral pulses 2
• Abdominal examination for distention, tenderness, masses, and bowel sounds 1
• Right upper quadrant assessment for Murphy sign 2

Laboratory and Imaging

• ECG is mandatory if any concern for cardiac etiology 2
• Cardiac troponin if ACS suspected 2
• Consider abdominal imaging only after excluding cardiac causes and if alarm features present (fever, weight loss, blood in stool, anemia) 2

Management Strategy

If Serious Causes Excluded

Initiate aggressive treatment for constipation with combination laxative therapy 1:

• Increase water and dietary fiber intake 2
• Add osmotic laxatives (polyethylene glycol preferred) 2
• Avoid multivitamin preparations with vitamin D if hypercalcemia suspected 2

For IBS-Type Symptoms

• Dietary modifications targeting specific triggers 2
• Stress management and psychological support if indicated 2
• Consider trial of antispasmodics or other symptom-directed therapy 2

Critical Pitfalls to Avoid

• Never assume benign cause without ECG in chest/upper abdominal pain 2, 1
• Do not use nitroglycerin response as a diagnostic criterion for cardiac vs. non-cardiac pain 2
• Recognize that young age does not exclude serious pathology 2
• Avoid delayed transfer for diagnostic testing if cardiac cause suspected 2
• Do not ignore "red flag" symptoms: fever, weight loss, blood in stool, severe sudden-onset pain 2