HPI: A 35 year-old female with a 1-week history of constipation, indigestion, back pain, and severe left-sided abdominal pain when rising from a seated position. She had a history of chronic headaches, back pain, and iron deficiency anemia (Hb 5.2; ferritin, 8 ng/mL) requiring transfusion 1 month ago. No fever, chills, or melena.

PMH: Current smoker, asthma requiring prednisone as needed (PRN), hx of peptic ulcer disease, SP hysterectomy, appendectomy, and cholecystectomy.

Medications: A prednisone taper for asthma exacerbation begun 1 month ago; Wellbutrin, methadone, and Celebrex for back pain; Fiorinal for headache

PE: In the emergency department (ER): temperature, 96.6; blood pressure, 136/83; heart rate, 100; lungs, clear, 95% O₂ saturation on room air, distended abdomen, guarding and rebound noted by ER physician

Diagnostic tests: WBC 20,100, 10% bands, Hb 10.6. PA chest and abdominal radiographs read in ER as “no free air, no infiltrates, normal bowel gas pattern, no mass, normal mediastinum.” EKG NSR with nonspecific ST-T changes.

Admission diagnosis: ER physician records “abdominal pain—acute.” The primary physician gave a preliminary diagnosis of gastroenteritis and constipation.