Accepted answer
Week 6 is day 42: on a four-week ladder that is week 2 of dose step 2, and — at the seven-day half-life this class runs on — 6 half-lives in. Steady state is about five half-lives, so day 35 is where the concentration stops climbing on its own. Day 42 is 1 weeks past it, which means the level is no longer the variable. That distinction is most of the question: at week 2 of a step, an effect that is still accumulating is indistinguishable from one that is not resolving unless you know which side of day 35 you are on. Constipation is the one that does not follow the escalation curve. It builds with cumulative exposure and with the fall in food and fluid volume, so it characteristically appears later than nausea and outlasts it by months. Dose decisions are made under supervision, and nothing here is medical advice.
Answering this needs the actual fibre and fluid intake, and people are almost always taking less of both than they think.
Magnesium-containing preparations act osmotically and are widely used; they are a laxative rather than a supplement in this context, and the dose is what makes the difference.
Red flags that change this from a management question to a clinical one: no bowel movement for several days with abdominal distension and vomiting, blood in the stool, or unexplained weight loss beyond what is expected.
The fibre-and-fluid relationship in functional constipation is established across intervention studies, and fibre without adequate fluid worsens symptoms.
Long-term stimulant laxative use is a clinical decision rather than a self-management default.
Pain, distension and vomiting together are urgent. That is not constipation.