Although intraperitoneal administration of sodium carboxymethylcellulose (SCMC) prevents the formation of adhesions following laparotomy in rats, it remains unknown whether SCMC treatment prevents the recurrence of preformed peritoneal adhesions following surgical lysis. Additionally, the optimal amount of SCMC required for adhesion prevention, as well as the effects of SCMC upon the healing of bowel anastomoses, has yet to be determined. To study this, 114 male rats underwent laparotomy and adhesion induction via peeling of the cecal serosa with a gauze sponge. Two weeks later, all animals again underwent laparotomy, the adhesions were graded, and surgical lysis of adhesions was performed. Following this, 3 to 12 ml of either normal saline or 1% SCMC solution was instilled into the peritoneal cavity prior to closure. A segment of small bowel was transected and reanastomosed prior to administration of SCMC or saline in another group of 70 rats. After an additional 2 weeks, the animals were sacrificed, the adhesions graded, and all the abdominal contents removed for fixation. The results show that treatment with high volume (i.e., 12 ml) intraperitoneal SCMC prevents reformation of adhesions following surgical lysis. This effect is demonstrated by a proportionate and significant decrease in the incidence of intraabdominal adhesions associated with administration of increasing amounts of SCMC (P < 0.05). While high volume SCMC did prevent adhesion of peritoneal structures to newly formed small bowel anastomoses, SCMC did not impair anastomotic healing. © 1995 Academic Press. All rights reserved.