The Impact of Laxative Use on Hospital Onset Clostridium Difficile Diarrhea

Background: Asymptomatic colonization with toxigenic Clostridium difficile is increasing. Relying solely on molecular based toxin testing may overdiagnose C. difficile infection (CDI). This study aimed at characterizing the use of laxatives and its outcomes in hospitalized patients diagnosed with CDI.

Methods: We reviewed charts of adult patients that met the CDC National Healthcare Safety Network definition for hospital onset C. difficile LabID event in 2015 at our institution. We retrieved data on laxative use 48 hours prior to CDI testing. We used chi-square and Mann-Whitney tests to compare clinical presentation and outcomes by laxative use. We used logistic regression to test whether laxative use was associated with poor outcomes (intensive care unit [ICU] admission, colectomy, death) after adjusting for sex, age and immunosuppression.

Results: Of 234 patients included in the study, 125 (53%) patients received laxatives prior to CDI testing. 105 (45%) patients had > 3 stools in 24 hours. Clinical presentation and outcomes by laxative use are shown in the Table. Laxative use was not associated with poor outcomes in multivariable analysis (OR, 0.77, 95% CI 0.4 – 1.6; P=.47).

Conclusion: A majority of patients with hospital onset CDI received laxatives 48 hours prior to testing suggesting the possibility of CDI overdiagnosis. Less than half of CDI patients had documentation of clinically significant diarrhea. Outcomes were no different by laxative use. Better education and documentation are needed to ensure C. difficile testing is done appropriately in accordance with SHEA/IDSA guidelines to minimize overdiagnosis and unnecessary treatment.

Table. Clinical presentation and outcomes by laxative use

Characteristic *	Laxative ( N= 125)	Non-Laxative ( N= 109)	P value
Age in years (IQR)	57 (41 – 68)	58 (44 – 66)	.96
Male sex	63 (50)	47 (43)	.27
≥ 3 stools in 24 hours	56 (45)	44 (40)	.49
Leukocytosis	50 (40)	32 (29)	.09
Leukopenia	17 (14)	20 (18)	.32
Fever > 100.4	19 (15)	5 (5)	.01
Abnormal abdominal exam	40 (32)	23 (21)	.06
Immunosuppression	27 (22)	31 (28)	.23
Colectomy	2 (2)	4 (4)	.31
ICU admission	9 (7)	8 (7)	.97
30-day readmission	3 (2)	3 (3)	.07
Length of Stay, days (IQR)	23 (11 – 40)	25 (12 – 48)	.35
Death	11 (9)	11 (10)	.74

* Data presented as n (%) unless specified.