Hypokalemia leading to torsades de pointes. Munchausen's disorder or bulimia nervosa?

A 45-year-old woman traveled over 1000 miles from a major metropolitan area to obtain another opinion for medically refractory diarrhea. She had an extremely complicated medical history with no outside records or family members accompanying her to give collateral history. She had multiple previous diagnostic evaluations including 13 surgical procedures and many therapeutic trials of various medications. She acknowledged a preoccupation with weight and appearance, described previous attempts to diet, and repetitively denied purging, including laxative abuse. During her hospitalization she had two episodes of torsades de pointes requiring cardiac defibrillation. Laboratory testing revealed hypokalemia at the time of these events, and a toxicology screen was positive for bisacodyl, confirming laxative abuse. When confronted by a combined team of cardiology, gastroenterology, and psychiatry specialist, she admitted her laxative abuse and surrendered her supply of Dulcolax tablets. The discussion addresses the procedures employed to detect her surreptitious medication use, the near lethal cardiac complications, and the appropriate psychiatric diagnosis.