What is the best course of action for a 55-year-old female with a history of diverticulitis presenting with low back pain radiating down her left leg, who has taken Motrin (ibuprofen) without relief and denies any injury?

Clinical Note: 55-Year-Old Female with Low Back Pain Radiating to Left Leg

Chief Complaint

This patient's presentation is consistent with lumbar radiculopathy (likely L5 or S1 nerve root compression), not diverticulitis-related pain, and requires focused evaluation of the lumbosacral spine rather than abdominal imaging.

History of Present Illness

• 55-year-old female presenting with low back pain radiating down the left leg
• Failed trial of ibuprofen (Motrin) for pain relief
• Denies traumatic injury
• Past medical history significant for diverticulitis

Clinical Assessment

Key Distinguishing Features

The radiation pattern down the leg is the critical diagnostic feature that differentiates this from diverticulitis:

• Diverticulitis typically presents with left lower quadrant abdominal pain, fever, and leukocytosis (though this classic triad occurs in only 25% of cases) 1
• Diverticular pain does not radiate down the leg in a dermatomal distribution 1
• The patient's pain pattern is consistent with lumbosacral radiculopathy affecting the sciatic nerve distribution

Red Flags to Assess

Evaluate for the following neurologic emergencies:

• Cauda equina syndrome: Assess for saddle anesthesia, bowel/bladder dysfunction, bilateral leg weakness, or progressive neurologic deficits
• Severe or progressive motor weakness: Document strength testing in all lower extremity muscle groups
• Fever with back pain: Could indicate spinal epidural abscess or discitis (though patient denies fever)

Physical Examination Priorities

Document the following specific findings:

• Straight leg raise test: Positive if pain radiates below the knee at <70 degrees of elevation
• Neurologic examination: Test sensation in L4, L5, S1 dermatomes; assess ankle dorsiflexion (L5), great toe extension (L5), and ankle plantarflexion (S1)
• Reflexes: Check patellar (L4) and Achilles (S1) reflexes
• Abdominal examination: Assess for left lower quadrant tenderness, fever, or peritoneal signs to exclude concurrent diverticulitis

Diagnostic Plan

Imaging Recommendation

MRI of the lumbosacral spine without contrast is the preferred initial imaging study for evaluating radicular symptoms with suspected nerve root compression.

• The history of diverticulitis is not relevant to this presentation unless the patient develops concurrent left lower quadrant pain, fever, or gastrointestinal symptoms 1
• CT abdomen/pelvis would only be indicated if she develops the classic diverticulitis triad of left lower quadrant pain, fever, and leukocytosis 1

Laboratory Studies (if indicated)

Consider the following if infection or inflammatory process suspected:

• Complete blood count with differential
• Erythrocyte sedimentation rate and C-reactive protein (if concern for infection/inflammation)
• Basic metabolic panel

Management Plan

Pain Management

The patient's failure to respond to ibuprofen requires escalation:

• Consider short course of oral corticosteroids (e.g., methylprednisolone dose pack) for acute radiculopathy
• Add neuropathic pain agent: gabapentin 300 mg TID, titrating up, or pregabalin 75 mg BID
• Consider short-term muscle relaxant: cyclobenzaprine 5-10 mg at bedtime
• Avoid NSAIDs if patient has active diverticular disease given increased risk of complications 1

Physical Therapy Referral

Early physical therapy improves outcomes in radiculopathy:

• Focus on core strengthening and nerve gliding exercises
• Avoid bed rest beyond 1-2 days

Specialist Referral Indications

Refer to spine specialist or neurosurgery if:

• Progressive neurologic deficits develop
• Cauda equina syndrome suspected
• Severe, disabling pain persists despite 6 weeks of conservative management
• MRI reveals significant nerve root compression requiring intervention

Diverticulitis Considerations

When to Suspect Diverticulitis Recurrence

The patient should return immediately if she develops:

• Left lower quadrant abdominal pain (distinct from back pain)
• Fever >100.4°F
• Inability to pass gas or stool
• Nausea, vomiting, or bloody stools
• Signs of peritonitis (guarding, rebound tenderness) 2

Preventive Measures for Diverticulitis

Given her history, counsel on risk reduction:

• High-quality diet rich in fruits, vegetables, whole grains, and legumes
• Maintain normal BMI through diet and exercise
• Regular physical activity
• Smoking cessation if applicable
• Avoid chronic NSAID use (relevant given her current pain management needs) 1

Critical Pitfall to Avoid

Do not attribute radicular leg pain to diverticulitis. Diverticulitis causes localized abdominal pain that may be associated with systemic symptoms, but does not cause dermatomal radiation down the leg 1. Misattributing this presentation to her diverticulitis history would delay appropriate diagnosis and treatment of her spinal pathology.