Constipation is often met with the same familiar advice: eat more fibre and drink plenty of water. But fibre is not a single, uniform nutrient – soluble and insoluble fibre work differently in the digestive system and can support gut health in distinct ways. Understanding how each type works and where to find it can help you make more informed choices when trying to improve bowel regularity and ease constipation.
Dr Joseph Salhab, a Florida-based gastroenterologist and health content creator who specialises in digestive, liver, pancreatic, and nutritional health, is breaking down the key differences between soluble and insoluble fibre , and how each type functions in the body. Two very different jobs. If you’re trying to improve constipation or have better bowel movements, it helps to understand the difference between soluble and insoluble fibre. Soluble fibre is a type of plant carbohydrate that dissolves in water to form a thick, gel-like substance in your digestive tract. Dr Salhab explains, “Soluble fibre is the stool shaper. They absorb water and form a gel. That helps make stool softer, smoother, and better formed. It also acts as a prebiotic, providing nourishment for beneficial bacteria in the large intestine. Additionally, soluble fibre may help lower cholesterol by binding to fatty acids and aiding their removal from the body. Insoluble fibre is a type of plant carbohydrate that does not dissolve in water, passing through your digestive system mostly intact to add bulk to your stool and help prevent constipation. Dr Salhab explains, “Insoluble fibre is the stool mover. They add bulk and help your colon move stool forward. It also helps move food through the digestive tract more efficiently, supporting regular bowel movements, reducing straining and potentially lowering the risk of certain digestive problems. “Most plant foods contain a mixture of both, so it isn’t a perfect split. But this is an easy way to think about fibre when you’re dealing with constipation, hard stool, irregular bowel movements , or trying to poop more consistently. Soluble fibre helps shape the poop. Insoluble fibre helps move the poop,” Dr Salhab concludes. Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. It is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them. Dr Joseph Salhab is a gastroenterologist providing services in central Florida. He received his medical degree from Lake Erie College of Osteopathic Medicine, Bradenton Campus, and has been in practice for over a decade. He has expertise in treating gastroenteritis and upper GI endoscopy, among other conditions.
In an Instagram post shared on August 27, the gastroenterologist explains, “Two types of fibre.
Soluble fibre slows the digestion and absorption of sugar, helping prevent sudden blood sugar spikes after meals, according to WebMD . Insoluble fibre draws water into the stool, making it softer, bulkier and easier to pass, according to Healthline .
