Zinberg 1990.

Study characteristics
Methods	Double‐blind, placebo‐controlled trial
Participants	Men and women, 18 to 75 years of age, with mild‐to‐moderate ulcerative colitis ‐ visible blood in the stool and disease involvement of 15 cm or more above the anal verge as defined by flexible sigmoidoscopy or colonoscopy (N = 15). The exacerbation could be a first instance or relapse of established disease. At least 3 days prior to participation, SASP, antidiarrheal agents, antispasmodics, and anticholinergics were discontinued. Oral or rectal steroids were not permitted within 1 week of study entry and other immunosuppressants were not permitted within 1 month of study. Concomitant medications not permitted during the study included NSAIDs, salicylates, digitalis derivatives, tranquilizers, and anti‐depressants At initial patient interview, history and physical exam were performed including baseline laboratory studies. Urine analysis for enteric pathogens was also performed
Interventions	Olsalazine (Pharmacia) in opaque gelatin capsules, each of 250 mg (n = 7) or indistinguishable placebo capsules (n = 8) in identical containers, 12 capsules/day (3 with each meal and 3 at bedtime) for 28 days Compliance was assessed by interview as well as by pill count
Outcomes	Evaluations were performed at the end of the 2nd and 4th weeks. Endoscopic evaluation was performed at entry and after 4 weeks Clinical evaluation included participant recordings of number of daily bowel movements, stool consistency, presence of blood and mucus, urgency, and incontinence. Endoscopic evaluation assessed the severity of ulceration, friability, erythema, and exudate, each on a 3‐point scale. The sum of these 3 scores gave a total endoscopic score. Improvement was assessed in terms of the changes in both clinical and endoscopic evaluations
Notes	Funding support and conflicts of interest were not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Low risk	Centralized randomization Randomization was on an alternate basis between drug and placebo and allocated by pharmaceutical manufacturer
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind: physically‐indistinguishable placebo capsules were provided in identical containers
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts balanced across intervention groups with similar reasons for withdrawal
Selective reporting (reporting bias)	Low risk	Expected outcomes were reported
Other bias	Low risk	The study appears to be free of other sources of bias

AE: adverse event; CAI: clinical activity index; CFT: contact friability test; EI: endoscopy index; ESR: erythrocyte sedimentation rate; IBD: inflammatory bowel disease; LOCF: last observation carried forward; MMDAI: modified Mayo disease activity index; PFA: patient functional assessment; PGA: physician global assessment; QOL: quality of life; SASP: sulfasalazine; UCCS: ulcerative colitis clinical score; UC‐DAI: ulcerative colitis disease activity index;