The best thing I can recommend is to take each side effect and treat it seprately so here are my tips:
Constipation, diarrhea and gas are all related so I trreat them together. Diarrhea can be controlled with over the counter anti diarrhea meds. You need to start at the first sign of diarrhea but be careful to not take too much as that can cause constipation. Constipation can be controlled with diet (fiber) and meds. Start with stool softener and forgress to more potent laxitives. Again be careful to not ovwer do it because you can easily get to diarrhea. With either diarrhea or constipation you can get gas and the meds may make that worse but it can be helped by over the counter gas meds. Again be careful to not take too much. With all of these issues I would avoid any first dates as you may make the wrong impression.
Nausea and vomiting are common with a lot of chemo regimes and can be controlled with anti nause meds that your DR can perscribe. Get two or three as different ones work fo different people. The key to anti nause meds is to take them at the first sign of nausea or event pre-emptively as it is easier to contriol the earlier you catch it.
With either diarrhea or vomiting you need to carefully watch for signs of dehydration as it can nit quickly and can land you in the hospital fast if not remedied. Be sure to drink lots of fluids and avoid diaruetics (things like caffene and nost sodas). Drinks like gatorade or just plain water are best.
I have not had much experience with bloating or weight gain. With diarrhea and vomiting I lost weight instead. I expwerienced a rare thing a Dr that liked it when I gained weight. The best way to contriol weight is through diet and exercise which are recommended in either case. As you start chemo and other treatments you will need to adjust both your fdood intake and your exercise as things change. Ask for a referal to a dietician and physical therapy if you need help with diet and exeercise.
I also have not had a bag so I can't giove advice from personal experience but here the obvious is to keep it clean as possible and to carry necessary cleaning supplies with you at all times. Don't count on there being the things you need when away from home.