What is the likely diagnosis and recommended management for a 40-year-old overweight female with a one-month history of crampy abdominal pain around the umbilicus and lower abdomen, radiating to the back, with a history of umbilical hernia, and a urine dipstick showing blood, but no nausea, vomiting, or weight loss?

Likely Diagnosis and Recommended Management

This patient most likely has urolithiasis (kidney stone) given the crampy periumbilical and lower abdominal pain radiating to the loin area with hematuria on dipstick, and the initial investigation should be a non-contrast CT scan of the abdomen and pelvis to confirm the diagnosis and exclude other serious pathology. 1

Critical Diagnostic Considerations

Primary Differential: Urolithiasis

• The combination of crampy abdominal pain radiating to the back/loin area with microscopic hematuria is highly suggestive of urolithiasis 1
• The progressive nature throughout the day with sudden onset episodes fits the classic pattern of ureteral colic
• Normal urination does not exclude stones, as partial obstruction can occur without complete urinary retention 1

Alternative Diagnoses to Exclude

Complicated umbilical hernia remains a concern despite non-palpable findings:

• Umbilical hernias can present with intermittent crampy abdominal pain, particularly when incarcerated or with fat necrosis 2
• In overweight patients, physical examination has limited sensitivity for detecting umbilical hernias 3
• Fat necrosis within an umbilical hernia can cause periumbilical pain without obvious external findings 2
• The history of documented umbilical hernia during pregnancy makes this diagnosis relevant 3, 4

Other considerations:

• Irritable bowel syndrome (IBS) presents with crampy abdominal pain that worsens throughout the day, but hematuria would be atypical 5
• The absence of nausea, vomiting, fever, and weight loss makes acute surgical emergencies like perforation or ischemia less likely 5, 1

Recommended Investigations

First-Line Imaging

CT scan of abdomen and pelvis with IV contrast is the recommended initial investigation 1:

• Superior for detecting urolithiasis, which is the most likely diagnosis given hematuria and radiation pattern 1
• Simultaneously evaluates for umbilical hernia complications including fat necrosis, incarceration, or strangulation 2
• Can identify other serious pathology including bowel obstruction, perforation, or vascular emergencies 1
• The World Society of Emergency Surgery recommends CT as first-line for acute abdomen evaluation when available 1

Laboratory Workup

Complete blood count and inflammatory markers 5:

• Leukocytosis would suggest infection, inflammation, or complicated hernia 5, 3
• Normal white count does not exclude urolithiasis or uncomplicated hernia 1

Comprehensive metabolic panel 6:

• Assess renal function given suspected urolithiasis
• Evaluate for electrolyte abnormalities

Formal urinalysis with microscopy 5:

• Confirm hematuria and assess for infection
• Crystals may suggest stone composition

Alternative Imaging if CT Unavailable

Ultrasound of abdomen and pelvis 6:

• Can detect hydronephrosis suggesting ureteral obstruction
• May visualize umbilical hernia and assess for complications 6
• Less sensitive than CT for stones and hernia complications 6, 1

Management Algorithm

If Urolithiasis Confirmed

• Analgesia (NSAIDs preferred if no contraindications)
• Hydration
• Medical expulsive therapy for stones <10mm
• Urology referral for stones >10mm or persistent symptoms

If Complicated Umbilical Hernia Identified

Surgical consultation is required 3, 4:

• Incarcerated or strangulated hernias require urgent surgical repair 4
• Fat necrosis may require elective repair depending on symptoms 2
• Emergency repair carries higher morbidity but is necessary for complications 4

If Both Investigations Normal

Consider IBS as diagnosis of exclusion 5:

• Rome IV criteria: recurrent abdominal pain at least 1 day per week in last 3 months, associated with change in stool frequency or form 5
• However, hematuria is not explained by IBS and warrants nephrology evaluation 5
• Exclude microscopic colitis if diarrhea develops 5

Critical Pitfalls to Avoid

Do not rely on physical examination alone to exclude umbilical hernia in obese patients 3, 2:

• Sensitivity of palpation is significantly reduced with increased body habitus
• Imaging is essential when hernia is documented historically but not palpable 2

Do not dismiss hematuria as insignificant 1:

• Even microscopic hematuria with appropriate clinical context warrants investigation
• Hematuria with flank pain has high specificity for urolithiasis 1

Do not delay imaging in favor of empiric treatment 1:

• The combination of pain severity, radiation pattern, and hematuria warrants definitive diagnosis
• Multiple serious conditions can present similarly and require different management 1

Recognize that normal bowel function does not exclude surgical pathology 5:

• Early obstruction or incarceration may not immediately affect bowel movements
• Progressive symptoms despite normal function warrant investigation 5