Table 2.

Upper panel: Differentiation of bowel function and fecal measurements in patients with mucosal diseases compared to functional diarrhea. Data shown are median (IQR). Microscopic colitis was included within the functional diarrhea cohort if patients were steroid-unresponsive. Lower panel: Primary bile acids ≤25% and total fecal bile acids ≤3033 µmol/48h has a 93% negative predictive value for ruling out mucosal disease. Patients with primary bile acids >25% and total fecal bile acids >3033 µmol/48h would require additional mucosal evaluation.

Parameter	Mucosal disease causing diarrhea	Functional diarrhea	P value,
N	135	936
# BM/day	6.5 (5–10)	5 (3.5–7.5)	<0.001
BSFS (7 point scale)	6 (5.9–7)	6 (5–7)	0.02
Fecal weight (g/48h)	776 (455–1263)	391 (247–601)	<0.001
Fecal Fat (g/24h)	14 (6–36)	6 (4–10)	<0.001
Primary BA (%)	43.5 (7.6–97.9)	4.5 (1.1–30.2)	<0.001
Total Fecal BA (µmol/48h)	3,067 ( 1126–7339)	1,015.5 (522–2130)	<0.001

	Mucosal Disease	No Mucosal Disease
Total fecal BA >3033 µmol /48h	73	131	PPV = 36% (73/204)
Total fecal BA ≤3033 µmol/48h	62	805	NPV = 93% (805/867)
	Sensitivity = 54% (73/135)	Specificity= 86% (805/936)
	Mucosal Disease	No Mucosal Disease
Primary BA > 25%	89	243	PPV = 36% (89/243)
Primary BA ≤ 25%	46	693	NPV = 94% (693/739)
	Sensitivity = 66% (89/135)	Specificity= 74% (693/936)

Bold numbers=IQR; BM=bowel movements; BA=bile acids; BSFS=Bristol Stool Form Scale

BA=bile acids; PPV=positive predictive value; NPV=negative predictive value