Abdominal Discomfort, Altered Bowel Habits, and Weight Loss in a 13-year-old Girl

A previously healthy 13-year-old girl is referred to pediatric gastroenterology by her primary care provider for evaluation of chronic generalized abdominal discomfort, early satiety, and bowel movements alternating between constipation and diarrhea. These symptoms have been worsening over a 4-month period. During these 4 months she has lost 40 lb and developed secondary amenorrhea. Physical examination is notable for emaciated appearance and...