I have recurrent, brief painful abdominal swelling that resolves within about five minutes—what is the likely diagnosis and how should it be evaluated and managed?

Recurrent Brief Painful Abdominal Swelling: Diagnosis and Management

Most Likely Diagnosis

Your presentation of recurrent, brief (5-minute) painful abdominal swelling that resolves spontaneously does not fit typical patterns of serious acute abdominal pathology and most likely represents either irritable bowel syndrome (IBS) or intermittent bowel spasm, though a ventral/incisional hernia with spontaneous reduction must be excluded if you have prior abdominal surgery. 1

Critical Initial Assessment

Rule Out Surgical Emergencies First

• Check for peritoneal signs (guarding, rebound tenderness, rigidity) which would indicate perforation or ischemia requiring immediate surgical consultation 1, 2
• Assess hemodynamic stability including heart rate and blood pressure, as tachycardia is the most sensitive early warning sign of surgical complications 2, 3
• Evaluate for true obstruction by asking about last bowel movement, passage of gas, and presence of vomiting—the combination has 85% sensitivity for adhesive small bowel obstruction if you have prior surgery 2, 3

Key Distinguishing Features

Your 5-minute duration argues against serious pathology because:

• Mesenteric ischemia presents with severe pain out of proportion to exam findings that does not resolve in minutes 1, 2
• Bowel obstruction causes colicky pain that waxes and wanes over hours, not minutes, with associated vomiting and inability to pass gas 2, 3
• Acute cholecystitis or appendicitis causes persistent pain lasting hours to days, not brief 5-minute episodes 2, 3

Differential Diagnosis Based on Episode Duration

Most Likely: Functional Bowel Disorder

IBS is diagnosed by Rome IV criteria requiring recurrent abdominal pain at least 1 day per week for the last 3 months, associated with two or more of: pain related to defecation, change in stool frequency, or change in stool form. 1

• The brief 5-minute duration with complete resolution suggests intestinal spasm or transient distension rather than structural pathology 1
• IBS affects 4.1-11% of the global population and commonly presents with visible abdominal distension 1
• Symptoms should be present for at least 6 months to distinguish from transient causes like infections 1

Must Exclude: Reducible Ventral Hernia

If you have prior abdominal surgery, a Spigelian hernia or other ventral hernia can present with brief episodes of pain and swelling that spontaneously reduce. 4, 5

• Spigelian hernias are difficult to diagnose as they may not present with obvious subcutaneous swelling 5
• These hernias carry high risk of incarceration and require surgical repair 4, 5
• The brief duration with spontaneous resolution fits a hernia that reduces on its own 5

Diagnostic Evaluation Algorithm

Step 1: Detailed History

• Duration of symptoms: Must be >6 months for IBS diagnosis 1
• Relationship to bowel movements: Pain relieved by defecation suggests colonic origin (IBS) 1
• Stool pattern changes: Associated changes in frequency or consistency support IBS 1
• Prior abdominal surgery: 85% sensitivity for adhesive obstruction or hernia risk 2, 3
• Timing of episodes: Morning "rush" with repeated defecation is characteristic of IBS 1
• Associated symptoms: Bloating, mucus passage, incomplete evacuation support IBS 1

Step 2: Physical Examination During and Between Episodes

• Examine during an episode if possible to palpate for hernia defect or localized mass 5
• Check for visible distension which has positive likelihood ratio of 16.8 for obstruction but also occurs in IBS 1, 2
• Palpate for fascial defects along the linea semilunaris (Spigelian hernia location) or prior surgical incisions 4, 5
• Assess for peritoneal signs which should be absent in functional disorders 1

Step 3: Mandatory Laboratory Testing

Order these tests to exclude organic disease:

• Complete blood count: Leukocytosis >14,000 suggests infection, ischemia, or inflammation 2, 6, 3
• Comprehensive metabolic panel: Low bicarbonate and elevated lactate indicate ischemia 2, 6, 3
• Pregnancy test (β-hCG): Mandatory in all women of reproductive age before imaging 2, 6, 3

Step 4: Imaging Strategy

If you have prior abdominal surgery or examination reveals a palpable defect:

• CT abdomen/pelvis with IV contrast is the imaging of choice to identify ventral hernias, Spigelian hernias, or other structural abnormalities 2, 3, 5
• CT changes diagnosis in 51% of patients with nonlocalized abdominal pain 2, 3

If no prior surgery and examination is normal:

• Imaging is not routinely indicated for suspected IBS with typical features and no alarm symptoms 1
• Consider imaging only if alarm features are present (see below) 1

Alarm Features Requiring Imaging

Proceed immediately to CT if any of these are present:

• Age >50 years with new-onset symptoms 1
• Documented weight loss 1
• Rectal bleeding 1
• Nocturnal symptoms that wake you from sleep 1
• Family history of colorectal cancer 1
• Anemia on laboratory testing 1
• Fever or signs of infection 2, 3

Management Based on Diagnosis

If IBS is Confirmed (No Structural Abnormality)

Management focuses on symptom control and reassurance:

• Dietary modification: Trial of low-FODMAP diet under dietitian guidance 1
• Antispasmodic agents: For pain relief during episodes 1
• Fiber supplementation: May help regulate bowel habits 1
• Psychological support: Chronic life stress virtually precludes recovery (0% vs 41% recovery rate) 1
• Reassurance: Explain that symptoms are real but not dangerous and do not lead to cancer or serious disease 1

If Ventral/Spigelian Hernia is Identified

Surgical repair is recommended due to high incarceration risk:

• Laparoscopic repair is advantageous with shorter hospital stay and lower wound infection rate compared to open repair 4, 7
• Transabdominal preperitoneal repair with mesh is the preferred technique for Spigelian hernias 5
• High patient satisfaction and low recurrence rates with surgical management 4, 7

If Diastasis Recti is Found

Conservative management is preferred unless cosmetic concerns are significant:

• Diastasis recti is not a true hernia and carries no strangulation risk 8, 9
• Exercise and physical therapy may improve symptoms in postpartum women 8
• Surgical repair is primarily for cosmetic reasons, not medical necessity 8, 9

Critical Pitfalls to Avoid

• Do not assume functional disorder without excluding hernia if prior abdominal surgery exists—Spigelian hernias are easily missed 5
• Do not delay imaging in patients with alarm features—colorectal cancer causes 60% of large bowel obstructions in older adults 2, 3
• Do not order plain radiographs—they have limited diagnostic value and rarely change management 2, 3
• Do not proceed with CT without pregnancy testing in women of reproductive age 2, 6, 3
• Do not diagnose IBS if symptom duration is <6 months—transient causes must be excluded first 1