Answering the narrow version, because the broad one does not have a single answer. The escalation order that reflects the mechanism: water and salt first, then soluble fiber, then magnesium or an osmotic agent, then a stimulant only briefly and only if the osmotic has failed. Stimulants first is the commonest error and the one most likely to end in a cycle of dependence.

Dr.RaviCardio said:

The escalation order that reflects the mechanism: water and salt first, then soluble fiber, then magnesium or an osmotic agent, then a stimulant only…

Drug interaction alert relevant to constipation: if you take oral levothyroxine (Synthroid), GLP-1 agonists can reduce absorption due to delayed gastric emptying. My TSH drifted up after starting semaglutide.

Solution: take levothyroxine on an empty stomach, 60 minutes before any food, and have your TSH rechecked 6-8 weeks after starting or changing GLP-1 dose. My endo had to increase my Synthroid by 12.5mcg.

amsterdam_pete said:

Constipation replaced nausea at around week five and has been the more persistent of the two by a wide margin.

Can confirm the pattern amsterdam_pete describes. Fiber trials in this population are thin, and most of what gets quoted is extrapolated from idiopathic constipation in people eating normally. The extrapolation is not unreasonable but it is an extrapolation, and it fails specifically for insoluble fiber at low intake — the case that comes up here most often.

From the other side of the consultation, briefly.

Sulfur burps on constipation — the most underrated side effect nobody warned me about. 🤢 The smell is absolutely vile and comes on without warning.

What finally helped: taking a digestive enzyme supplement. Also, eating smaller portions and chewing thoroughly reduces the gas production.

If sulfur burps persist beyond 2-3 weeks, talk to your provider — it could indicate gastroparesis that needs medical attention.