Constipation on GLP-1: pathophysiology and evidence-based management

Taking the question as asked, rather than the general version of it. 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.

I would rather be corrected than agreed with, if it comes to it.

pete_manc_UK 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…

Acid reflux and constipation: I developed GERD symptoms around week 7 that I'd never had before. The delayed gastric emptying means food and acid sit in your stomach longer.

Management that works for me: elevate head of bed 6 inches, don't eat within 3 hours of lying down, avoid trigger foods (tomato, citrus, spicy, chocolate), and famotidine 20mg at bedtime. Much better now.

Dr.GutHealth said:

The mechanism is slowed transit plus reduced intake, and that combination determines which interventions work.

This matches mine closely enough to be worth saying so. 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.

Adding the clinical framing, because it changes how the question reads.

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: Gas-X (simethicone) daily. 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.