IBS-C
Also called: IBS with constipation, constipation-predominant IBS
IBS-C is the constipation-predominant subtype of irritable bowel syndrome. People with IBS-C have abdominal pain or discomfort with hard or lumpy stools more than 25 percent of the time and loose stools less than 25 percent of the time. About a third of all IBS cases sit in this subtype. The fix is usually a combination of soluble fibre, hydration, movement and (sometimes) targeted medication.
How IBS-C is diagnosed
IBS-C is a clinical diagnosis using the Rome IV criteria: recurrent abdominal pain at least 1 day a week for 3 months, related to defecation, with a stool-form pattern that is mostly hard or lumpy (Bristol stool types 1 to 2) and rarely loose (types 6 to 7). Coeliac disease, inflammatory bowel disease, and other organic causes are ruled out with blood tests, faecal calprotectin and (in some cases) colonoscopy.
What it feels like
- Bloating that builds through the day and eases overnight.
- Hard, lumpy or pellet-like stools, often with strain.
- A feeling of incomplete emptying after a bowel movement.
- Cramping that improves after going.
- Fewer than 3 bowel movements a week, often.
- Symptoms cluster around stress, hormonal cycles, and certain foods (FODMAPs).
What helps
- Add 25 to 30 grams of fibre a day, mostly from oats, kiwi, flax, chia, psyllium, beans and pulses.
- Drink 2 litres of water across the day. Hydration is what makes fibre useful, not harder.
- Walk 30 minutes daily. Gut motility is dose-responsive to movement.
- Try a 4-week low-FODMAP elimination under a dietitian if symptoms persist after the basics. Reintroduce systematically.
- Daily psyllium husk (5 to 10 g) or magnesium citrate (400 mg) at bedtime if the basics aren't enough.
- Consider prescribed laxatives (linaclotide, plecanatide, prucalopride) under specialist care if lifestyle and OTC options have failed.
What does not help
- Low-fibre diets long-term. They reduce stool bulk and worsen IBS-C in most people.
- Senna or stimulant laxatives daily. Useful as rescue, but tolerance builds and they can worsen the cycle.
- Cutting all fermented foods. Most IBS-C patients tolerate them fine; the problem is FODMAPs in specific foods, not fermentation generally.
- Probiotics without a strain target. Some strains (especially B. infantis 35624) help; most don't move the needle.
Common questions
- What's the difference between IBS-C and just being constipated?
- IBS-C requires abdominal pain that is related to defecation. Functional constipation can have hard stools without that pain pattern. The treatment overlaps but IBS-C also benefits from low-FODMAP and gut-brain therapies that don't change ordinary constipation.
- Can IBS-C turn into IBS-D?
- Yes. IBS subtypes can switch over time, often around stress, illness, or after antibiotics. About 30 percent of IBS patients change subtype within 5 years.
- Does IBS-C affect women more than men?
- Yes, by about 2 to 1. Hormonal influence on gut motility (especially in the luteal phase) is part of the reason. Many women find their IBS-C cycles with their periods.
- Is IBS-C the same as slow transit constipation?
- Related but not identical. Slow transit constipation is mainly a motility problem (food moves too slowly through the colon). IBS-C is a motility AND visceral sensitivity problem (the same gas and stool feels more painful). Diagnosis is clinical.
Sources
- NICE CG61: irritable bowel syndrome in adults (NICE)
- British Society of Gastroenterology IBS guidance (BSG)
- Rome IV criteria for IBS (Rome Foundation)
- Low-FODMAP diet evidence base (Monash) (Monash University)