Below is my total list of what I try to eat and avoid eating when taking opioids (Tramadol) that promote constipation.

Some of these are easy to have on hand in storage in case you unexpectedly get a flare up and must take the Tramadol.

To eat to help alieviate constipation:
warm liquids in morning
fruit and vegetables
prunes, prune juice
figs
seeds
bran
fresh, canned, dried fruits
fruits w skin or seeds
raw, cooked veg
apricots
peas
chia seeds
corn
wild rice (completely wild, get in health food stores, not wild and white rice mixture)
beans
pears
broccoli
flax
spinach, chard, kale
asparagus
raw carrots
kiwi

Avoid: (or take if you have diarrhea and want to firm up)
Dairy
Caffeine
Processed Foods
Bananas
White Rice
Apple Sauce
Toast
Baked Potato
Mashed Potatoes
Eggs

If you are really challenged, sitting on the toilet with your feet up on a couple of big yellow pages telephone books helps the process along more comfortably and avoids hemorrhoids. (Isn't this a lovely topic?)

If you know for sure the Tramadol will bring strong constipation from past experience, then it helps to take a very mild laxative early on / ahead of time. It is much easier and more comfortable to prevent this problem and avoid it from the start, then try to later fix several days of constipation.

However, I also don't think laxatives are a great idea either. So instead I try to be prepared by having some of the things above on hand that store well and quickly take them from the start and continue taking them (you are very unlikely to overdo it with natural foods) and prevent the problem naturally.

My body seems to be much happier with me for this.

Natalie