purpose: to analyze the effects of sodium hyaluronate and carboxymethylcellulose membrane on collagen and fibroblast formation in bowel suture healing in rats. methods: 48 male wistar rats, weighing 250 to 343g, were randomized into two groups: group i - bowel suture without applying a biologically absorbable membrane and group ii - bowel suture with application of an absorbable membrane. the two groups were divided into subgroups of 3, 14 and 30 days of observation, with 8 rats in each subgroup. all were sacrificed after the end of the observation period. results: no morbidity or mortality was observed during the experiment. the amounts of collagen in group i were 23.4%, 72.1% and 67.6% and in group ii were 22.5%, 52.5% and 51.6%, for the subgroups of 3, 14 and 30 days, respectively. comparison between groups showed that the 14-day (p=0.0013) and 30-day (p=0.0587) subgroups had significant variance, with larger collagen zones in animals in which the membrane was not applied. however, with regard to fibroblasts, group i had 2%, 13% and 8% and group ii had 2%, 10% and 8%, for the 3-day (p=1.0), 14-day (p=0.3184) and 30-day (p=0.5995) subgroups, respectively, showing no significant variance. conclusion: the use of the biologically absorbable membrane cause a decrease in collagen formation, while not altering the number of fibroblasts, in bowel suture healing in rats, without increased morbidity and mortality.