Constipation

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Connected to · 2

cofactor · 1

Carbs & Fiber
The colon moves waste along while reclaiming water, and what keeps water in the stool is the gel formed by soluble fiber, especially psyllium husk. In a meta-analysis of randomized trials (van der Schoot 2022), psyllium gave adults with chronic constipation about three extra bowel movements a week. What does the work is the fiber's viscosity, not its fermentation.
Mechanism · 3
Mechanism · Why psyllium works
The colon pushes waste forward while taking water back. The longer stool sits, the more water is drawn out, and the drier and harder to pass it becomes; Bharucha 2020 describes slow transit and water reabsorption as one loop. What holds water in the bowel is a highly viscous soluble gel. Psyllium husk is a high-viscosity, low-fermentation fiber: its gel reaches the rectum intact and acts as a lubricant, precisely because bacteria cannot digest it (Marlett 2000). That is why it relieves constipation without much gas, while an easily fermented fiber such as inulin feeds bacteria, produces gas and does little for constipation.
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Numbers · How much and how to add it
van der Schoot 2022 updated the pooled randomized trials of fiber supplements for chronic constipation in adults: fiber increased the number of bowel movements and improved stool consistency and straining, with psyllium husk standing out at about three extra bowel movements a week; doses above 10 g a day worked best. The key is to drink more water at the same time and to start with a small dose and build up slowly, because a sudden large increase can cause more bloating. The aim is not to reach the target in a day but to add a little each week while drinking enough water.
Clinical · When fiber is not the answer
Not every case of constipation calls for fiber. In a defecatory disorder, the pelvic floor muscles tighten when they should relax, so extra fiber and laxatives often fail and pelvic floor biofeedback is needed; Bharucha separates this type from slow transit. Fiber without enough water cannot form its gel, and the stool may become even harder. When lifestyle changes plus psyllium are not enough, the 2023 guideline from the American Gastroenterological Association (AGA) and the American College of Gastroenterology (ACG) strongly recommends the osmotic laxative polyethylene glycol (PEG, moderate certainty of evidence), not a colon-cleanse tea.

regulates · 1

Hemorrhoids
Constipation and long straining are the most often named triggers of hemorrhoids: in the sliding-lining theory, pushing down again and again gradually loosens the tissue that holds the anal cushions, and they swell and slide down. Conversely, fiber that softens stools cut the risk of hemorrhoid bleeding by 50% across 7 randomized trials.

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What counts as constipation

EVIDENCEGUIDE 1 · REVIEW 1

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Constipation is more than a few days without a bowel movement. It is a cluster of signs that passing stool has become hard: a lot of straining, dry and hard stool, a feeling that you have not fully emptied, or very few bowel movements a week.

It happens in the large intestine (the colon). Food residue moves through the colon too slowly, too much water is drawn back out of it, and the stool turns dry and hard. The vast majority of constipation is functional: the bowel's structure is fine, it is just running slowly. On its own it is mostly not dangerous, and it is not toxins building up inside you.

One situation cannot wait: if you suddenly cannot pass gas or stool at all, with severe abdominal pain and vomiting, it may be an emergency — seek care at once. Blood in the stool, black stool, or unexplained weight loss also need a doctor promptly.

Educational content, not medical advice — consult a clinician.

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