Hypothyroidism-Induced Stercoral Sigmoid Colonic Perforation

According to the Centers for Disease Control and Prevention, abdominal pain is the leading reason for ED visits in the United States, with approximately 10 million visits per year.¹ Though a large number of presentations are due to nontraumatic causes of abdominal pain, one etiology is among the most time-sensitive and critical diagnoses: acute colonic perforation.

Colonic perforations can be caused by diverticulitis, trauma, malignancy, ulcerative colitis, and other etiologies.² A rare, yet life-threatening cause of colonic perforation, of which only a few cases have been documented in the literature, is stercoral colonic perforation.²

Regardless of the etiology, the critical actions for any colonic perforation are quick recognition, medical stabilization, and surgical evaluation. This case report highlights the diagnosis and treatment of acute stercoral colonic perforation with peritonitis secondary to hypothyroidism.

Case

A 49-year-old woman with a medical history significant for hypothyroidism presented to the ED for evaluation of diffuse abdominal pain, nausea, and nonbilious, nonbloody vomiting that started in the early evening of presentation. The patient denied any previous pain or associated symptoms, and said she had a small, hard bowel movement 1 day prior to arrival. She began experiencing mild abdominal pain on the morning of presentation. Her symptoms acutely worsened at approximately 5:00 pm. She denied having any diarrhea, melena, or hematochezia. Her surgical history was significant for a cesarean delivery. She denied any history of small bowel obstruction. The patient admitted that she had stopped taking levothyroxine (150 mcg daily) prescribed for hypothyroidism approximately 1 month earlier, but had been restarted on it approximately 2 to 3 days prior to her presentation.

On physical examination, her vital signs were: heart rate, 156 beats/min; blood pressure, 134/84 mm Hg; respiratory rate, 20 breaths/min, and temperature, 97.4°F. The patient appeared ill and diaphoretic, writhing on the stretcher. Abdominal examination was significant for diminished bowel sounds, diffuse abdominal distension, rigidity, and tenderness with light palpation.

Laboratory evaluation showed an elevated lactic acid level of 7.7 mmol/L, a white blood cell count of 7,200 cells/mm³ (segment form, 69.5%), and the following abnormal blood chemistry results: creatinine, 2.08 mg/dL; aspartate aminotransferase, 176 U/L; alanine aminotransferase, 138 U/L; and thyroid-stimulating hormone (TSH), 225.3 mcIU/mL. Other laboratory results were within normal range. Her electrocardiogram showed sinus tachycardia with a rate of 154 beats/min, a QTc within normal limits, and no ST elevations or depressions.

An abdominopelvic computed tomography (CT) scan revealed free air, free fluid, and possibly stool within the abdomen and pelvis. The findings were consistent with a ruptured hollow viscus, possibly a sigmoid colonic perforation. The radiologist also noted hepatomegaly and significant hepatic steatosis. A surgeon was immediately notified and evaluated the patient in the ED. The working diagnosis was stercoral colonic perforation secondary to severe hypothyroidism, and the patient was taken emergently to the operating room for repair.

Intraoperatively, the patient underwent exploratory laparotomy, which revealed gross fecal contamination of the abdomen. The surgeon noted that there was fecal staining along the serosal surface of the small bowel and throughout the pelvis. There were also large, hard stool balls outside of the colon. The perforation was along the mesenteric surface of the sigmoid just above the rectosigmoid junction.

The abdomen was copiously irrigated, the perforated segment was resected, and a Hartmann colostomy was created. The diagnosis was stercoral sigmoid perforation with peritonitis, and the patient was transferred to the intensive care unit for antibiotic treatment and further medical care, including intravenous (IV) levothyroxine.

She was extubated uneventfully on postoperative day 2, and the acute renal failure improved with supportive care only. Her bowel function slowly returned without complication. She was switched to oral levothyroxine on postoperative day 3. On day 13, she was given strict instructions for continuation of her thyroid medication and close monitoring for postsurgical complications, and was discharged home with appropriate follow-up.

Discussion

Multiple contributing factors can lead to bowel perforation. In this case, severe hypothyroidism with constipation caused a colonic perforation. Our patient had severe constipation that increased intraluminal pressure, causing the bowel wall to become ischemic and subsequently perforate.³ Any disease that causes significant constipation or obstruction of transit could lead to the same catastrophic result.