Pain in the left iliac fossa

Specialty: Gastrointestinal.

• Pain in left lower quadrant
• colonic diverticular pain
• left iliac fossa pain

Why it occurs

• Acute sigmoid diverticulitis due to micro or macroperforation of a diverticulum in the descending/sigmoid colon (classically known as "left-sided appendicitis")
• Irritable bowel syndrome with severe spasm of the sigmoid colon
• Segmental ischemic colitis with involvement of Griffith's point (splenic flexure and proximal descending colon due to low perfusion)
• Left adnexal pathology (complicated left ovarian cyst, left adnexal torsion, salpingitis)
• Severe constipation with fecal impaction and inflammation of the sigmoid mucosa due to local fecalith (stercolitis).

Initial workup

CT of the abdomen and pelvis with intravenous contrast (absolute study of choice to evaluate diverticulitis, stage according to the modified Hinchey classification and plan medical or surgical management; acute colonoscopy is contraindicated due to high risk of perforation) | Emergency analysis: blood count, CRP, procalcitonin, serum lactate, kidney function and electrolytes | Transvaginal or suprapubic pelvic ultrasound (essential in women to rule out left gynecological origin) | Standing chest x-ray (to look for pneumoperitoneum under the diaphragmatic domes in case of suspected free perforation).

Standard management

• Systemic empiric antibiotic therapy for acute diverticulitis — metronidazole 500 mg IV every 8 hours plus ciprofloxacin 400 mg IV every 12 hours, or ceftriaxone 2 g IV every 24 hours; alternatively amoxicillin/clavulanic acid 1.2 g IV every 8 hours, given for 7 to 10 days
• Non-opioid analgesics — metamizole 1-2 g IV or paracetamol 1 g IV to avoid the use of opioids such as morphine that increase colonic intraluminal pressure and aggravate constipation
• Osmotic laxatives at low doses after acute phase — polyethylene glycol to prevent the formation of hard stools impacted in the sigmoid, totally contraindicated in the acute obstructive phase
• Strict liquid diet or therapeutic fasting with supportive intravenous fluid therapy.