I'm sorry to hear that your feeling so bad. It's can't be easy have IBS and going through a op. There was someone on here who had really bad C after a op. She tried miralax which helped her. I'd check with your doc about taking first.
Are you on the IBS dirt yet? Increasing your soluble and since your C insoluble fibre should help. Starting with the acacia fibre is a good step.
Try the fennel tea for the bloating - it's meant to really help.
Exercise is also really important with C. You can also start do some easy yoga poses. I find the one labeled wind reliving pose really helps. Downward dog is also good do reliving gas. http://www.helpforibs.com/yoga/poses.asp