The connection between constipation and fiber is greatly exaggerated. In intestinal physiology, not only the mechanical fibers of food play a key role, but also the mineral balance, as well as the functioning of nerve and hormonal regulation.
People on a Carnivore or keto diet can do without plant fiber and have no problems with stool. This is because the intestine adapts: with a low volume of bulk substances, gas production decreases and stool volume reduces, but it does not become hard and "stuck" if there are enough minerals and fats.
With low fiber intake, stool becomes less frequent, but not necessarily painful – this is a variant of normal.
The role of minerals in the development of constipation
Constipation is more often associated with electrolyte imbalances, which directly regulate peristalsis and stool consistency.
Magnesium. One of the main "anti-constipation" minerals:
- Activates the parasympathetic nervous system, stimulating intestinal motility.
- Attracts water into the intestinal lumen (osmotic effect), making stool softer.
- In case of magnesium deficiency, smooth muscle spasms and slowed peristalsis occur.
Potassium. Necessary for generating nerve impulses and the functioning of intestinal muscle cells. Potassium deficiency → intestinal atony, sluggish peristalsis, and chronic constipation. Potassium losses (for example, due to diuretics or excess sugar/caffeine) are a common hidden cause of constipation.
Calcium. Its excess in the presence of magnesium deficiency can provoke constipation, as calcium promotes muscle contraction, and without sufficient magnesium, relaxation does not occur.
The balance of Ca/Mg is critically important: with calcium dominance, "hard," dry stool occurs.
Sodium and water. Adequate salt intake maintains water balance. With low sodium, intestinal contents lose moisture, and fecal masses become dry.
Iron. Excess iron (especially in the form of supplements) is one of the most common medication-related causes of constipation.
Additional factors:
- Fats stimulate bile secretion, which is a natural laxative.
- Protein, with sufficient enzymes and acidity, does not cause constipation, but with weak gastrointestinal secretion and mineral deficiency, it can slow down stool.
- The hormonal background (hypothyroidism, high cortisol) also affects intestinal motility.
Constipation is not so much a "lack of fiber" as it is a disruption of mineral and water balance.
