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Does fibre help or worsen constipation at very low intake?

Asked 10 Nov 2025Modified 8 months agoViewed 13k times
This question was closed as primarily opinion-based.Closed 18 Dec 2025. Answers already posted are preserved; new answers are not accepted. Questions here need a factual basis on which they can be answered.
20

I have kept a symptom diary against dose dates, which turns out to have been the useful thing.

Both of these get recommended confidently by different people, which suggests neither is obviously right.

My constraints are cost, measurement resolution and how much handling I am prepared to do — in roughly that order.

Under what conditions does the answer flip?

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askedseven_day_half16k1810 Nov 2025

3 Answers

Accepted answer first, then by votes
33

Accepted answer

Timing is the most useful diagnostic feature here and it is the one most often omitted from the question.

Constipation outlasts the nausea because it has two causes and only one of them resolves. Gastric emptying accommodates over weeks; total intake, and therefore stool volume and the osmotic load reaching the colon, does not recover until intake does. This is why fibre alone can make it worse — you add bulk to a system that is short of water and short of motility.

Gastrointestinal adverse events, indicative pooled rates

EventActive armPlacebo armTiming
Nausea40–45 %15–20 %Peaks 1–2 wk after each step
Vomiting15–25 %5–8 %Follows nausea
Diarrhoea20–30 %10–15 %Early, variable
Constipation20–25 %8–12 %Later onset, persistent
Discontinuation for GI events4–7 %1–2 %Mostly during escalation

Ranges span agents and doses; read the specific prescribing information for a specific figure.

Mechanically, distinguishing an injection-site nodule from an infection: a nodule is firm, non-tender or mildly tender, not warm, not expanding, and appears within a day or two. Cellulitis is warm, tender, expanding, and often accompanied by systemic features. A sterile abscess sits between the two and is fluctuant. Warmth plus expansion plus fever is the combination that stops being a forum question.

SURMOUNT-1 reported gastrointestinal events as the most frequent adverse events, mostly mild to moderate and mostly during escalation, with discontinuation for adverse events in the single digits per cent[1].

One qualification — reported incidence in a monitored trial population is a lower bound on what happens in an unmonitored one, because trial participants were escalated to protocol and supported through it.

A symptom diary with dates against dose steps answers most of these questions without anyone needing to guess.

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answered · acceptedforty_units14k1725 Nov 2025
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28

Concretely, the mechanism explains the pattern. Delayed gastric emptying plus central appetite suppression produces early satiety, and early satiety plus a slowed transit produces exactly the symptom cluster people report.

Nausea incidence in the pivotal trials runs to roughly 40 to 45 per cent at the higher doses against 15 to 20 per cent on placebo, with vomiting at roughly 15 to 25 per cent against 5 to 8 per cent. Discontinuation specifically attributable to gastrointestinal adverse events was in the range of 4 to 7 per cent. Those are the numbers to hold in mind when someone describes their experience as unusual.

On the detail: the telogen effluvium timing signature is the diagnostic feature: hair enters the shedding phase two to four months after the insult, so shedding that starts at month three of rapid loss and peaks around month four to five is the expected pattern. Shedding that starts in week two is not telogen effluvium and warrants a different question. In either case the follicle is not destroyed and regrowth is the rule.

The prescribing information for each agent lists adverse reaction frequencies against placebo in a table, and reading that table is more informative than reading a hundred anecdotes, because it has a denominator.

The caveat that actually matters: this is pattern recognition from published data, not a clinical assessment of you. Anything severe, persistent or accompanied by systemic features belongs with a clinician the same day.

Fix the fixable causes first — fluid, electrolytes, sleep, intake — before concluding that the compound is responsible.

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answeredines_brandt93k24814 Nov 2025
Two of us worked through this independently and arrived here, so it is at least reproducible. – ravi_pillai 2 months ago
Worth adding that the method section is where the answer usually is. – tess_amankwah 3 months ago
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15

In practice, look at the placebo arm before concluding anything about attribution. The placebo-arm rates for most of these events are not small, because the events themselves are common in the underlying population.

The gallbladder signal tracks the rate of weight loss more than it tracks the drug. Rapid mobilisation of adipose tissue increases biliary cholesterol saturation and reduces gallbladder motility; that combination is lithogenic whether the loss came from a drug, a very-low-energy diet or bariatric surgery. The drug contribution on top of that is present but smaller than the rate contribution.

Vomiting matters mostly through its consequences. Loss of gastric fluid depletes sodium, chloride and potassium, and hypokalaemia presents as exactly the fatigue and cramping people attribute to the drug. Persistent vomiting also makes a renal panel uninterpretable, because a pre-renal picture looks like renal impairment.

I would flag that attributing a symptom to a drug is a hypothesis, and the base rate of these symptoms in the general population is high enough that the hypothesis is often wrong.

If the timing does not fit the escalation, look for another explanation before settling on the drug.

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answeredcake_collapsed13k286 Dec 2025

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.