>>52704294>eat fiber, does next to nothingWhat are you eating for fiber?
To rule out fiber requirements, try consuming oats, up to 200g (weighed dry) per day cooked in water or blended raw for a few days.That should give you the shits. If not, stop eating it and cut down to say 100g for breakfast.
Now you've ruled out fiber as a cause, try and consume 2L of water per day. Dehydration can cause your body to absorb more water from the digestive tract. Sip it throughout the day and keep it on your desk.
Next thing would be to look at intolerances that commonly cause constipation. I'd start with dairy which can cause all kinds of strange things - some constipation, others loose stools.