The placebo effect. Is it important in diverticular disease?
Thirty patients with diverticular disease confirmed by barium enema examination were entered into a three-month double-blind trial of two tablets of methylcellulose (Celevac) daily or two placebo tablets daily. As these tablets were indistinguishable it was possible to cross over nine of the patients and follow them for a further three-month period. The placebo effect was sufficient for 11 patients who completed the trial on placebo to show a small mean improvement. A greater mean clinical improvement was shown, however, by the 16 patients who completed the trial on methylcellulose and in those who were crossed over, most of the improvement occurred during the time the patients were on methylcellulose.