What is irritable bowel syndrome (IBS)?

What is IBS?

Irritable Bowel Syndrome (IBS), is a functional bowel disorder which causes chronic or recurrent abdominal pain and symptoms such as gas, bloating, diarrhea, and constipation at least one day a week. With IBS: 

• The pain often improves after a bowel movement
• Your symptoms are associated with changes in your stool form or appearance (watery, loose, or hard to pellet-like)
• You have a change in stool frequency (you have to go more or less often) 

IBS affects millions of people worldwide, primarily women under 50 . It’s not clear exactly what triggers IBS, but potential causes include: 

• Inflammation in your gut caused by an infection
• Genetics
• Increased intestinal permeability (leaky gut)
• Problems digesting certain foods
• An imbalance in the microbiome (dysbiosis) might cause changes in how your intestines move waste along, increased sensitivity in your GI tract, or changes in your gut-brain axis. 

Are there different types of IBS?

 There are three main types of IBS, characterised based on your bowel patterns: 

• IBS with diarrhea (IBS-D)
• IBS with constipation (IBS-C)
• IBS with mixed bowel habits (IBS-M). 

What is constipation?

Constipation is a change in your bowel habits or stool consistency. You have fewer than three bowel movements a week along with stool that is hard, dry, and difficult or painful to pass. You may also feel like not all stool has passed.¹

What is the gut-brain axis, and how does it affect IBS?

The gut-brain axis is a communication link between your central nervous system (your brain and spinal cord) and your enteric nervous system, which controls your digestive tract. Your gut and brain are connected through a complex system of nerves and chemical messengers. There is also evidence that your gut microbiota can affect your gut-brain axis.²

This system helps manage the muscle contractions in your digestive tract that control the movement of food and waste. It also manages the nerves that sense pain in your intestines. Because the gut-brain axis is a two-way communication system, feelings of stress or anxiety can affect how your gut works and the degree of abdominal pain you feel.

What are the best probiotic species and strains for IBS?
There is clinical evidence that certain species and strains of probiotics can support the improvement of IBS symptoms. For example: 

• L. plantarum reduced abdominal pain and bloating in a four-week study.⁴ A 12-week study showed it reduced the severity of abdominal pain by 67%, diarrhea by 70%, and constipation by 79%. It's also worth noting that L. plantarum may help improve the quality of life in those with IBS. People who took this probiotic reported a 110% improvement in mental well-being after 12 weeks.⁵ Adults diagnosed with functional constipation reported more regular bowel movements after supplementing with the probiotic B. lactis for 28 days, compared to those who took a placebo.⁶
• After 12 weeks, adults with moderate to severe IBS-related pain who took the probiotic L. acidophilus reported significantly less abdominal pain compared to those who took a placebo.⁷