A 16-year-old girl is brought to the office by her mother due to constipation. The patient has had bowel movements twice a week for the past 2 months. She has no abdominal pain but states her stomach is "puffing up." Her mother says the patient appears tired and wears multiple layers of clothing despite the warm weather. Medical history is significant for acne vulgaris treated with topical retinoids. Temperature is 36 C (96.8 F), blood pressure is 90/60 mm Hg, pulse is 54/min, and respirations are 16/min. BMI is 18 kg/m². On physical examination, the abdomen is scaphoid and nontender with normal bowel sounds. Which of the following is the most likely diagnosis for this patient?

Question

Quizplus · Accepted Answer

11ec25c8_d30c_c90c_bc81_89695543743b_MD0003_00 This young woman with constipation has bradycardia, borderline hypotension, and cold intolerance (eg, wearing multiple layers despite warm weather). Along with her low body weight (BMI <18.5 kg/m²) and distorted body image (eg, saying her stomach is "puffing up" when it is scaphoid on examination), this presentation is suggestive of anorexia nervosa (AN). Gastrointestinal complications of AN are extremely common; decreased food intake and/or electrolyte abnormalities often results in slowed colonic transit time and constipation. Other typical gastrointestinal complications include gastroparesis, gastroesophageal reflux, and elevated liver function tests. ² Because individuals with AN often try to keep their disorder hidden from others, it is also important to be aware of the possible physical signs of AN, which include abnormal vital signs, emaciation, lanugo, dry skin, hair loss, arrhythmias, and parotid gland enlargement (when purging is present). In medically stable patients, first-line treatment includes nutritional rehabilitation and psychotherapy. (Choice B) Autonomic neuropathies are most common in patients with uncontrolled diabetes mellitus. Gastrointestinal manifestations include gastroparesis (eg, postprandial nausea, early satiety), and diarrhea; constipation is unexpected. In addition, autonomic neuropathy typically causes tachycardia, not bradycardia. (Choice C) Functional constipation does not explain this patient's low body weight, distorted body image, or abnormal vital signs. (Choice D) Hypothyroidism can also present with constipation, cold intolerance, and bradycardia. However, it is typically associated with weight gain and diastolic hypertension; this patient's low body weight and blood pressure combined with her distorted body image are more suggestive of AN. (Choice E) Although irritable bowel syndrome can cause alterations in bowel habits (eg, constipation, diarrhea), it is characterized by the presence of abdominal pain. In addition, irritable bowel syndrome would not be expected to cause abnormal vital signs, cold intolerance, or low body weight. (Choice F) Partial small bowel obstruction can cause intermittent constipation but typically presents with abdominal pain, distension, nausea, and tympanic bowel sounds. It usually occurs in the setting of prior abdominal surgery or Crohn disease. Educational objective: Anorexia nervosa (AN) is characterized by low body weight, distorted body image, and avoidance of weight gain. Because patients with AN often try to hide their disorder, associated signs and symptoms (eg, constipation, cold intolerance, bradycardia, hypotension) are important diagnostic clues. References: Gastrointestinal complications associated with anorexia nervosa: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/26407541) Defecatory disorders in anorexia nervosa: a clinical study. (http://www.ncbi.nlm.nih.gov/pubmed/24030784) Medical complications of anorexia nervosa. (http://www.ncbi.nlm.nih.gov/pubmed/27166107)

A 16-Year-Old Girl Is Brought to the Office by Her