Can a pulled muscle in the lower back cause abdominal pain in a patient with a history of left-sided abdominal pain and potential diverticulitis or inflammatory bowel disease?

Can a Pulled Muscle in the Lower Back Cause Abdominal Pain?

Yes, a pulled muscle in the lower back can absolutely cause abdominal pain through referred pain patterns, but in a patient with left-sided abdominal pain and a history concerning for diverticulitis or inflammatory bowel disease, you must first exclude serious intra-abdominal pathology with CT imaging before attributing symptoms to musculoskeletal causes.

Critical Distinction: Musculoskeletal vs. Intra-Abdominal Pathology

The key clinical challenge is that musculoskeletal abdominal wall pain can mimic intra-abdominal disease, and vice versa. However, given the patient's history of potential diverticulitis or IBD, the stakes of missing serious pathology are too high to assume a benign musculoskeletal cause without imaging.

When Musculoskeletal Pain Should Be Suspected

Abdominal wall pain has specific diagnostic features that distinguish it from visceral pain 1:

• Pain provoked by physical movement of the trunk or abdominal muscles 1
• Localized to a circumscribed site in the abdominal wall that can be pinpointed with one finger 1
• Pain increases when abdominal muscles are tensed (positive Carnett's sign) 1
• Reproducible with digital palpation at a specific trigger point 1

Specific Musculoskeletal Patterns That Refer to the Abdomen

Lower back muscles can produce abdominal pain through well-documented referred pain patterns 2:

• Quadratus lumborum trigger points are the most common muscular cause of low back pain and can refer pain to the lower abdomen 2
• Lower rectus abdominis trigger points refer pain horizontally across the low back 2
• Iliopsoas trigger points refer pain in a vertical pattern parallel to the lumbosacral spine 2
• Fibro-fatty nodules ("back mice") in the lower back can cause severe acute lower abdominal pain through referred mechanisms 3

Why You Cannot Assume Musculoskeletal Cause in This Patient

The American College of Radiology rates CT abdomen and pelvis with IV contrast as 8/9 (usually appropriate) for left lower quadrant pain with a broad differential diagnosis 4. This is critical because:

Overlapping Presentations Create Diagnostic Confusion

• Diverticulitis and IBD can present with atypical symptoms that may seem musculoskeletal 4
• Clinical examination alone has a 34-68% misdiagnosis rate for abdominal pain when imaging is not performed 5
• CT alters the diagnosis in approximately 50% of patients with nonlocalized abdominal pain 4

The Consequences of Missing Serious Pathology

In patients with left lower quadrant pain, the most common serious causes include 4:

• Acute diverticulitis (most common cause in adults) with potential for perforation and mortality 4
• Inflammatory bowel disease (Crohn's disease or ulcerative colitis) requiring specific treatment 4
• Colitis, bowel obstruction, or abscess requiring urgent intervention 4
• Overlap syndromes where diverticulitis and IBD coexist, complicating diagnosis 6

Recommended Diagnostic Algorithm

Step 1: Perform Focused Physical Examination

Look for red flag features that mandate immediate CT imaging 4:

• Fever or leukocytosis (suggests infection/inflammation) 4
• Inability to pass gas or stool (suggests obstruction) 7
• Severe tenderness with guarding or rebound (suggests peritonitis) 7
• Bloody stools or signs of shock 7

Step 2: Test for Musculoskeletal Origin

If no red flags are present, perform these specific maneuvers 1:

• Carnett's test: Have patient tense abdominal muscles by lifting head/shoulders off table while you palpate the painful area. If pain increases, this suggests abdominal wall source. If pain decreases, this suggests visceral source 1
• Identify if pain is localized to anatomic sites prone to musculoskeletal strain: semilunar line, linea alba, rectus muscle, or costal arch 1
• Assess if pain is reproduced by trunk rotation or lateral bending 1

Step 3: Obtain CT Imaging in This Patient

Even if musculoskeletal features are present, this patient requires CT abdomen and pelvis with IV contrast because 4, 5:

• History of potential diverticulitis or IBD creates high pretest probability for serious pathology 4
• CT has 98-100% sensitivity for diverticulitis and can detect subtle pericolonic fat stranding missed on clinical exam 5
• CT identifies alternative diagnoses in up to 49% of cases, including early Crohn's disease, epiploic appendagitis, or mesenteric adenitis 5
• The overlap between IBS-type symptoms and diverticular disease makes clinical diagnosis unreliable 8

Step 4: Management Based on Findings

If CT is completely normal and musculoskeletal features are present 5, 1:

• Reassure the patient that serious pathology is excluded 5
• Treat as musculoskeletal pain with NSAIDs, physical therapy, and activity modification 1
• Consider trigger point injection if a discrete nodule is identified 3

If CT shows diverticulitis or IBD 5:

• Manage according to specific findings (conservative management for uncomplicated diverticulitis in immunocompetent patients) 5
• Gastroenterology referral for IBD management 5

Common Pitfalls to Avoid

• Do not assume musculoskeletal cause based on history of "pulled muscle" alone in a patient with risk factors for serious abdominal pathology 4
• Do not rely on ultrasound for left-sided abdominal pain, as it is operator-dependent and cannot adequately visualize the colon, mesentery, or retroperitoneum 5
• Do not dismiss persistent or recurrent pain even if initial evaluation suggests musculoskeletal origin—consider repeat imaging if symptoms persist 7
• Recognize that anxiety about chronic unexplained pain can develop and may complicate the clinical picture 1