Chronic constipation presenting with severe abdominal pain

Abstract

An 80-year-old African American male presents with severe abdominal distention and no bowel movement or gas per rectum for 3 days, as well as recent onset of vomiting. He has Parkinson’s disease and chronic constipation and lives in a nursing home. His medications include levodopa and benztropine, which he has been taking for several years. On physical examination, the patient’s vital signs are T 37°C, P 90/min, BP 116/70 mmHg, RR 22/min, and SpO2 99 % (room air). He appears to be tachypneic but otherwise nontoxic, with mental status unaltered from his baseline. Lungs are clear to auscultation bilaterally. His abdomen is severely distended. He does not have any abdominal surgical scars. He is tympanitic but has no significant tenderness to palpation. There are no palpable hernias, and rectal exam demonstrates an absence of stool with no palpable masses or strictures. Laboratory tests include metabolic panel with BUN 26 mg/dL (normal 7-21 mg/dL), Cr 1.4 mg/dL (0.5-1.4 mg/dL) and electrolytes within normal limits, WBC 6.8x103/µL (normal 4.1-10.9x103/µL), venous lactate 0.9 mEq/L (0.5-2.2 mEq/L), and ABG pH 7.48//PaCO2 30//PaO2 80//HCO3 24//SpO2 99 %. A plain upright abdominal radiograph shows a massively dilated loop of sigmoid with apex pointing toward the right upper quadrant, consistent with "coffee bean" sign; upright chest radiograph shows no free air under the diaphragm.