I struggle with opiate constipation due to my daily suboxone. But before that, it was due to heroin. What I find works best for me, is a daily fiber supplement, with plenty of water.
The supplement I use suggests 1 scoop / 4 oz of whatever, and 5 scoops / day (max). The powder is flavorless and really has no texture, so it can be added to anything (water, juice, cereal, yogurt) and there's no issue with flavor/texture. That is something I use everyday to ensure I poop regularly (once / day ... Before opiates I pooped 2 - 3 x / day)!
However, I'd also recommend trying dulcolax once (just to clear out), or even once a month if this continues. With dulcolax, it's important you are well-hydrated because it can induce pretty painful cramping. I use to be able to take 1 dulcolax before bed, and wake up 8 hours later to an urgent need to shit: VOOSH! Flushes you out, effortlessly, and you feel reborn! The recommended dose is 1 - 3 pills, but the higher the dose, the more likely you are to wake up with some painful cramps. However, if one pill doesn't flush you out, I'd try taking 2 pills before bed the following night. 3 dulcolax just doesn't seem necessary, lol.
Good luck!