An 80-year-old woman is brought to the emergency department due to diarrhea. The patient has advanced Alzheimer dementia and is cared for by her daughter at home. Her daughter reports that the patient has had 6-8 nonbloody, watery bowel movements a day for the past several days. The patient has had multiple hospitalizations for similar symptoms in the past 6 months; in each case, evaluation was negative for infection, and symptoms resolved within a few days. Home medications include donepezil and memantine. Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 104/min, and respirations are 18/min. Physical examination shows dry mucous membranes. Heart and lung sounds are normal. The abdomen is soft and nontender. Laboratory evaluation shows hypokalemia and metabolic alkalosis. C-reactive protein and fecal calprotectin are unremarkable. The patient is hospitalized, and intravenous fluids and potassium replacement are begun. Colonoscopy shows dark brown mucosal pigmentation in the proximal colon but is otherwise unremarkable. Which of the following is the most appropriate next step in management of this patient?

Question

An 80-year-old woman is brought to the emergency department due to diarrhea.  The patient has advanced Alzheimer dementia and is cared for by her daughter at home.  Her daughter reports that the patient has had 6-8 nonbloody, watery bowel movements a day for the past several days.  The patient has had multiple hospitalizations for similar symptoms in the past 6 months; in each case, evaluation was negative for infection, and symptoms resolved within a few days.  Home medications include donepezil and memantine.  Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 104/min, and respirations are 18/min.  Physical examination shows dry mucous membranes.  Heart and lung sounds are normal.  The abdomen is soft and nontender.  Laboratory evaluation shows hypokalemia and metabolic alkalosis.  C-reactive protein and fecal calprotectin are unremarkable.  The patient is hospitalized, and intravenous fluids and potassium replacement are begun.  Colonoscopy shows dark brown mucosal pigmentation in the proximal colon but is otherwise unremarkable.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

This patient has had multiple hospitalizations for diarrhea associated with dehydration (eg, dry mucous membranes) and electrolyte abnormalities (eg, hypokalemia, metabolic alkalosis). Colonoscopy shows melanosis coli, which suggests anthraquinone (eg, senna) laxative abuse. Excessive use of anthraquinones causes colonic epithelial damage and the release of a brown pigment (lipofuscin) into the lamina propria that can be visualized on colonoscopy. It takes several months of abusing anthraquinones to develop melanosis coli, and it disappears when the laxatives are discontinued. Because this patient has advanced dementia and is cared for primarily by her daughter, evidence of laxative abuse raises the possibility of factitious disorder imposed on another (FDIA). FDIA is characterized by the induction or falsification of illness in another person, typically a family member. As in factitious disorder imposed on self, illnesses in FDIA are induced to obtain not a tangible benefit (eg, financial compensation, access to controlled substances) but psychologic validation or facilitation of the sick/caregiver role. Children are most commonly the victim in FDIA, but elderly patients may also be abused in this manner. The victim must be protected from further harm, and in this case, adult protective services should be notified. (Choice A) Steatorrhea (ie, increased fecal fat levels) occurs in malabsorptive disorders such as pancreatic insufficiency and celiac disease. This patient's stools are not typical of steatorrhea (eg, greasy, foul-smelling), and malabsorptive disorders do not cause melanosis coli. (Choice B) Although memantine can cause loose stools, it does not cause melanosis coli and is unlikely to result in this patient's diarrhea. (Choice D) VIPoma is a neuroendocrine tumor that causes persistent secretory diarrhea. This patient's intermittent diarrhea is atypical for VIPoma, and melanosis coli would be unexpected. (Choice E) Inflammatory bowel disease, which can be treated with glucocorticoids (eg, budesonide), presents with diarrhea associated with hematochezia, abdominal pain, and elevated inflammatory markers (eg, C-reactive protein, fecal calprotectin). It only rarely causes melanosis coli. Educational objective: Melanosis coli is an abnormal brown pigmentation of the colon due to excessive use of anthraquinone (eg, senna) laxatives. Factitious disorder imposed on another is characterized by the causation or falsification of illness in another person, typically a family member, to obtain psychologic validation or facilitation of the sick/caregiver role. The victim must be protected by notifying protective services. References: Melanosis coli: a helpful contrast effect or a harmful pigmentation? (http://www.ncbi.nlm.nih.gov/pubmed/30574001) Munchausen syndrome by proxy-illness fabricated by another in older people. (http://www.ncbi.nlm.nih.gov/pubmed/27856413)

An 80-Year-Old Woman Is Brought to the Emergency Department Due