Nine patients complaining of constipation and with diverticuli of the colon on barium-enema were examined with regard to transit-time, bowel movements and subjective symptoms. They were treated with placebo and Vi-SiblinR, using a doubleblind cross-over technique. The transit-time remained normal during the Vi-SiblinR treatment. The feces became softer and increased in weight and the subjective symptoms were significantly reduced (p less than 0,05).