AIM: In colorectal surgery, anastomotic failure is still a problem in ischemia. Here, we analyzed the effects of hyperbaric oxygen and beta-glucan on colon anastomoses in ischemic condition. METHODS: Colonic resection and anastomosis in rectosigmoid region were done in forty Wistar-Albino rats of four groups of equal number. Colon mesentery was ligated to induce ischemia. The first group was the control group. The subjects of second group were treated with hyperbaric oxygen; the third group with glucan and the forth group were treated with both. At the forth day, rats were sacrificed, anastomotic segment was resected and burst pressures and hydroxyproline levels of anastomotic line were measured. RESULTS: The burst pressure difference of second and third groups from the control group were meaningful (P<0.01); the forth group differed significantly from the control (P<0.001). There was no difference between the treated groups on burst pressure level (P>0.05). The hydroxyproline levels in all treated groups were different from the control group significantly (P< 0.001). Hydroxyproline levels in the forth group were higher than those of the second and the third groups (P< 0.001). There were no significant differences between the second and the fourth groups in burst pressure and hydroxyproline levels (P>0.05). CONCLUSION: Hyperbaric oxygen and glucan improve healing in ischemic colon anastomoses by anti-microbic, immune stimulating properties and seem to act synergistically when combined together. AIM: In colorectal surgery, anastomotic failure is still a problem in ischemia. Here, we analyzed the effects of hyperbaric oxygen and beta-glucan on colon anastomoses in ischemic condition. METHODS: Colonic resection and anastomosis in rectosigmoid region were done in forty Wistar- The first group was the control group. The subjects of second group were treated with hyperbaric oxygen; the third group with glucan and the forth group were treated with both. At the forth day, rats were sacrificed, anastomotic segment was resected and burst pressures and hydroxyproline levels of anastomotic line were measured. RESULTS: The burst pressure difference of second and third groups from the control group were meaningful (P <0.01); the forth group differed significantly from the control (P <0.001). There was no difference between the treated groups on burst pressure level (P> 0.05). The hydroxyproline levels i n all treated groups were different from the control group significantly (P <0.001). Hydroxyproline levels in the forth group were higher than those of the second and the third groups (P <0.001). There were no significant differences between the second and the fourth groups in burst pressure and hydroxyproline levels (P> 0.05). CONCLUSION: Hyperbaric oxygen and glucan improve healing in ischemic colon anastomoses by anti-microbic, immune stimulating properties and seem to act synergistically when combined together.