What could be causing left-sided abdominal pain from the uterus to the ribs that worsens when laying on the right side in a curled up position?

Left-Sided Abdominal Pain Worsened by Right Lateral Position

Your positional pain pattern—left-sided abdominal discomfort from the uterus to ribs that worsens when lying curled on your right side—most likely represents either gastroesophageal reflux disease (GERD) or a musculoskeletal/abdominal wall pain syndrome, though imaging may be needed to exclude structural causes like diaphragmatic hernia or gynecologic pathology.

Most Likely Diagnoses Based on Positional Pattern

Gastroesophageal Reflux (Most Probable)

• Lying on the right side significantly increases gastroesophageal reflux, with total reflux time more than doubled (231 minutes right-sided vs. 117 minutes left-sided) and prolonged acid clearance (0.77 min/episode right-sided vs. 0.29 min/episode left-sided) 1
• The curled position may further increase intra-abdominal pressure, exacerbating reflux symptoms that radiate from the epigastrium up to the left chest/rib area 1
• This explains why your pain specifically worsens in the right lateral decubitus position 1

Abdominal Wall Pain Syndrome

• Positional pain that relates to lying, sitting, or standing strongly suggests abdominal wall origin rather than visceral pathology 2
• Abdominal wall pain frequently presents with a localized tender trigger point but can radiate over a diffuse area 2
• Key diagnostic test: Carnett's sign—if your tenderness is unchanged or increased when you tense your abdominal muscles, the abdominal wall is the likely source 2

Structural Causes Requiring Exclusion

Diaphragmatic Pathology

• Left-sided diaphragmatic hernias can present with nonspecific gastrointestinal symptoms including pain that may be positional 3
• Chest X-ray has only 2-60% sensitivity for left-sided hernias, so CT scan is the gold standard with 14-82% sensitivity and 87% specificity 3
• CT findings include diaphragmatic discontinuity, intrathoracic herniation of abdominal contents, and the "collar sign" 3

Gynecologic Causes (If Reproductive Age)

• Ovarian or adnexal pathology (torsion, cysts, endometriosis) can cause left lower quadrant pain radiating upward 3
• Endometriosis can cause architectural distortion and positional discomfort 3
• Initial imaging should be transvaginal ultrasound if gynecologic etiology suspected, with specificity above 90% 3

Recommended Diagnostic Approach

Initial Clinical Assessment

• Check for Carnett's sign: Have someone palpate the tender area while you perform a partial sit-up; if pain increases or stays the same, abdominal wall pain is likely 2
• Assess relationship to meals and acid reflux symptoms (heartburn, regurgitation) 1
• Determine if pain is truly positional or also related to eating, bowel movements 2

Imaging Strategy Based on Clinical Suspicion

If symptoms suggest reflux or musculoskeletal origin:

• Trial of proton pump inhibitor therapy for GERD 1
• Local anesthetic injection at trigger point for abdominal wall pain (diagnostic and therapeutic) 2

If red flags present or diagnosis unclear:

• CT abdomen and pelvis with IV contrast is the most appropriate initial imaging for nonlocalized left-sided abdominal pain, with ability to detect diverticulitis (>95% sensitivity), hernias, and other structural pathology 3, 4
• CT can evaluate for diaphragmatic hernia, though dedicated chest CT may be needed if high suspicion 3

If reproductive age with gynecologic concerns:

• Transvaginal ultrasound first, followed by CT or MRI if inconclusive 3

Critical Pitfalls to Avoid

• Do not assume benign cause without excluding structural pathology in patients with persistent, severe, or progressive symptoms 4
• Pregnant patients require special positioning considerations: After 20 weeks gestation, avoid supine positioning during procedures due to aortocaval compression risk; use left lateral tilt 3
• The elderly may present atypically with normal laboratory tests despite serious pathology 3
• Unenhanced CT has similar accuracy to contrast-enhanced CT in elderly patients (64-68% vs. 68-71%) if contrast is contraindicated 3

When to Pursue Urgent Imaging

Obtain CT abdomen/pelvis with IV contrast urgently if you experience 3, 4:

• Fever with abdominal pain
• Severe, unremitting pain
• Signs of peritonitis (guarding, rebound tenderness)
• Inability to tolerate oral intake
• Associated vomiting or bowel obstruction symptoms