I have digestive issues from my teeth to my butthole. GERD, gastritis, IBS, diverticulosis, hemorrhoids... that I know of. Everything that I do now has been discussed and approved by my doctors, I recommend you do the same with yours.
I take one serving of Metamucil in the morning to help with my IBS. Depending on which variety you choose, that could be between one teaspoon and one tablespoon. I've been told that, depending on your situation, too much fiber can actually make it harder to have a BM. That is actually the case with me. Sometimes a second dose in the afternoon is beneficial to me, sometimes not.
Also in the morning, I mix Miralax into my coffee. Currently that is about one teaspoon (about 1/3 of a serving). Again, sometimes I need to increase that amount, sometimes decrease it. It took me a long time to figure out how much of this to take. Once changing the amount of the dose, I'd recommend you change nothing else for a few days. It takes awhile for your body to adjust and regulate.
I do this everyday, and it is easy enough to take these meds with me on vacation. It is definitely a hassle and not ideal, but it is better than being constipated, bloated, in pain, nauseous, etc. Get started by asking your doctor(s) if this something that might work for you.