1. Adverse events.

Study	Pts. in experimental group	Pts. in control group	AE in experimental group	AE in control group	Author's conclusion
Beuers 1992	6	8	Diarrhoea (1 pt.)	No Ae	The symptoms ceased after UDCA treatment termination.
Lo 1992	8	10	No AE	No AE	UDCA seemed to be well tolerated.
Stiehl 1994	10	10	Diarrhoea (2 pts.)	No AE	After a reduction of the dose to 500 mg and 250 mg/day, UDCA was well tolerated. Re‐exposure to the higher dose (750 mg) re‐induced diarrhoea.
Lindor 1997	53	52	No AE	Diarrhoea (1 pt.), flare of ulcerative colitis (1 pt.)	Ursodiol was well tolerated.
Mitchell 2001	13	13	No AE	No AE	No patients required alteration in the prescribed trial medication for diarrhoea or any other cause.
Olsson 2005	110	109	37	34	There seemed to be no difference between the two groups in the overall frequency of reported side effects attributed to the capsules (UDCA, 38.1%; placebo 33.7%)
Charatcharoenwitthaya 2008	42	No‐controls	Flare of ulcerative colitis (1 pt.)	No controls	UDCA was well tolerated, but one patient stopped medication after four years of therapy because of a flare of ulcerative colitis.

pt(s) = patient(s). 
 AE = adverse events.