Factitious diarrhea is an intentionally self-inflicted disorder which is motivated either internally by assuming a sick role or externally by money, health benefits, etc. The keys to diagnosis are suspicion and use of readily available stool and urine tests. Since factitious diarrhea is not uncommon and many tests used to evaluate chronic diarrhea are invasive and expensive, it is reasonable to perform a series of basic studies to evaluate for factitious diarrhea early in such an evaluation. Surreptitious laxative use is the most common etiology of factitious diarrhea and can present with volume depletion and an altered biochemical profile. Magnesium-containing laxatives will cause osmotic diarrhea; a high stool osmolar gap and stool magnesium level of more than 90 Meq/L will be present. Stimulant laxatives may cause non-gap diarrhea and can easily be detected in the urine. Any osmolality less than normal (290 mOsmol/kg) indicates dilutional diarrhea, usually the addition of urine or water to stool. All cases of factitious diarrhea should be well documented in the medical record to avoid future unnecessary testing.
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American Psychiatric Association. American Psychiatric Association. Task Force on DSM-IV. Diagnostic and statistical manual of mental disorders: DSM-IV, 4th edn. Washington DC: American Psychiatric Association, 1994.Google Scholar
Savino AC, Fordtran JS. Factitious disease: clinical lessons from case studies at Baylor University Medical Center. Proc Bayl Univ Med Cent 2006; 19(3): 195–208.PubMedGoogle Scholar
Phillips SF. Surreptitious laxative abuse: keep it in mind. Semin Gastrointest Dis 1999; 10(4):132–137.PubMedGoogle Scholar
Phillips S, Donaldson L, Geisler K, Pera A, Kochar R. Stool composition in factitial diarrhea: a 6-year experience with stool analysis. Ann Intern Med 1995; 123(2):97–100.PubMedGoogle Scholar
Duncan A, Cameron A, Stewart MJ, Russell RI. Diagnosis of the abuse of magnesium and stimulant laxatives. Ann Clin Biochem 1991; 28(Pt 6):568–573.PubMedGoogle Scholar
Keswani RN, Sauk J, Kane SV. Factitious diarrhea masquerading as refractory celiac disease. South Med J 2006; 99(3):293–295.PubMedCrossRefGoogle Scholar
Bytzer P, Stokholm M, Andersen I, Klitgaard NA, Schaffalitzky de Muckadell OB. Prevalence of surreptitious laxative abuse in patients with diarrhoea of uncertain origin: a cost benefit analysis of a screening procedure. Gut 1989; 30(10): 1379–1384.PubMedCrossRefGoogle Scholar
Santangelo WC, Richey JE, Rivera L, Fordtran JS. Surreptitious ipecac administration simulating intestinal pseudo-obstruction. Ann Intern Med 1989; 110(12): 1031–1032.PubMedGoogle Scholar
Schiller LR, Santa Ana CA, Porter J, Fordtran JS. Validation of polyethylene glycol 3350 as a poorly absorbable marker for intestinal perfusion studies. Dig Dis Sci 1997; 42(1):1–5.PubMedCrossRefGoogle Scholar
Ryan CM, Yarmush ML, Tompkins RG. Separation and quantitation of polyethylene glycols 400 and 3350 from human urine by high-performance liquid chromatography. J Pharm Sci 1992; 81(4):350–352.PubMedCrossRefGoogle Scholar
Shelton JH, Santa Ana CA, Thompson DR, Emmett M, Fordtran JS. Factitious diarrhea induced by stimulant laxatives: accuracy of diagnosis by a clinical reference laboratory using thin layer chromatography. Clin Chem 2007; 53(1):85–90.PubMedCrossRefGoogle Scholar
Beyer J, Peters FT, Maurer HH. Screening procedure for detection of stimulant laxatives and/or their metabolites in human urine using gas chromatography-mass spectrometry after enzymatic cleavage of conjugates and extractive methylation. Ther Drug Monit 2005; 27(2):151–157.PubMedCrossRefGoogle Scholar