SallyK_inj said:

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

Gastroparesis symptoms with constipation: the delayed gastric emptying from GLP-1 agonists can cause early satiety, bloating, and feeling "full" for hours after a small meal.

Tips: eat your protein FIRST (most important macro), then vegetables, then carbs last. Chew thoroughly — 20-30 chews per bite isn't excessive. Avoid carbonated beverages with meals. If symptoms are severe, your doctor may recommend a gastric emptying study.

Following on from sophie_paris — and this may be the naive question:

What the mechanism is, because if it is transit rather than water then fiber is the wrong lever?

raj_cambridge said:

Gastroparesis symptoms with constipation: the delayed gastric emptying from GLP-1 agonists can cause early satiety, bloating, and feeling "full" for…

Heartburn management on constipation: Pepcid (famotidine) 20mg has been my savior. The delayed gastric emptying means stomach acid just sits there.

Don't ignore persistent heartburn — chronic acid exposure can damage your esophagus. If OTC remedies aren't cutting it after 2 weeks, see your doctor for something stronger. You shouldn't suffer through this.

Closing the loop on my own question.

Resolved: water and magnesium first, soluble fibre second, bran gone entirely. Two months of doing it in the wrong order and a week to undo.

NurseAsh_DET said:

Heartburn management on constipation: Pepcid (famotidine) 20mg has been my savior.

Gastric emptying studies and constipation: semaglutide delays gastric emptying by ~40% at steady state, as measured by acetaminophen absorption testing and scintigraphy[1].

Clinically relevant implications:

• Explains early satiety and nausea
• Affects absorption of co-administered oral medications
• Creates aspiration risk for procedures under anesthesia
• Contributes to constipation via slowed GI transit

Importantly, the gastric emptying delay attenuates with continued use (tachyphylaxis), which correlates with the transient nature of GI side effects.