If you just had surgery, then you must be in the one-month rest period between surgery and the beginning of adjuvant chemotherapy. You didn't mention it, but I assume that you will be continuing on with adjuvant chemotherapy in a month or so.
I had an ileostomy, so I cannot answer your main question about post-surgery experience without an ostomy bag. However, I have my own opinions, based mainly on what I would call common sense.
What I would say is that in the next few months you would need to make sure that you do not eat anything that is going to get stuck in the newly formed anastomosis junction or that would cause that part of the neo-rectum to expand too much. One of the cautions I think, would be to always eat several small meals instead of one large one. If you eat a large meal, it is likely to eventually end up transiting through your neo-rectum as a large mass of stool that may cause too much pressure on the new junction. Also, I think that you should probably avoid high residue foods with big chunks, such as trail mix snacks, muesli, pineapple chunks, etc. Whatever you eat, you should be sure to chew it very, very well so that it doesn't end up being an undigested mass. Also, I think that it would be a good idea to try to avoid foods that cause a lot of gas, since if a big volume of gas ends up in the neo-rectum area near the anastomosis junction then it might put too much pressure on the junction. Of course, you should also avoid foods that are known to cause constipation, since a large, constipating stool passing through the neo-rectum junction would probably put excessive pressure on the junction.
These are just a few suggestions off the top of my head, As I said above, these suggestions are not based on actual experience similar to yours. They are based on some of the things I went through after my ileostomy reversal, when I had to manage what went through the newly patched-up part of my rectum.
Another point: Now that you have completed the surgery, you should get a written copy of the pathology report from your surgery and discuss it with your doctor. There will be many new medical terms to learn, but most of them are very important in determining your risk level for possible future recurrences. The pathology report is what the doctors look at very closely when they are trying to determine the best regimen to use for mop-up adjuvant therapy. You should ask your oncologist what regimen they have planned for you. If it is either Folfox of Xelox, then it would contain oxaliplatin. In that case you might want to discuss methods of reducing the oxaliplatin dose or doing an oxaliplatin desensitization protocol, because the side effects of oxaliplatin can be rather bothersome.