
Living Positively with IBS-M
What is IBS-M?
Irritable bowel syndrome (IBS) is a functional gut disorder that affects the lower portion of the gastrointestinal tract, which includes the small and large intestines. There is nothing structurally wrong with the gut, but rather, there’s something wrong with how the gut moves and senses digestion. This can lead to symptoms of bloating, abdominal pain, and changes in bowel habits like constipation, diarrhea, or both.
Subtypes of IBS are recognized by the Rome IV criteria based on the person’s reported predominant bowel habit, when not on medications, as follows:
- IBS-C: with predominant constipation (Bristol types 1 and 2).
- IBS-D: with predominant diarrhea (Bristol types 6 and 7).
- IBS-M: with both constipation and diarrhea (Bristol types 1 and 6).

IBS-M (the M stands for ‘mixed’) is a subtype when a person with IBS suffers from alternating diarrhea and constipation. Nearly everyone has suffered from diarrhea or constipation at one point or another, however, if these are constant, recurring problems, you may suffer from IBS-M. Especially, if these problems are paired with other symptoms, such as bloating, cramping and abdominal pain.
People who suffer from IBS-M can switch from constipation to diarrhea, often very quickly, and tend to suffer more stomach pain than someone who suffers from IBS-D (diarrhea) or IBS-C (constipation).
Possible Causes of IBS-M
The underlying cause of IBS is still unclear and there is no diagnostic disease markers for IBS. However, some potential factors include things like food sensitivities, a disruption in the brain-gut connection, genetics, stress, infections, or an unbalanced microbiota.
How is IBS-M Diagnosed?
Your physician will first conduct a careful review your medical history and a physical examination. Utilizing IBS diagnostic algorithms, such as the Rome Foundation’s Diagnostic Criteria for Functional Gastrointestinal Disorders and excluding any “red flags” suggesting other disorders, your physician will then establish a diagnosis of IBS based on your symptoms.
Doctors can make the diagnosis with a high degree of certainty, based on experience with treating IBS. Tests that may be required include to rule out other digestive conditions include:
- A blood test may be conducted to rule out celiac disease.
- If the onset is relatively recent, your doctor may order stool cultures to exclude an ongoing infection.
- If you are suspected of being lactose intolerant, your doctor may order testing to exclude this (breath test or blood test).
- If you have a family history of diseases such as celiac disease, Crohn’s disease, ulcerative colitis or colon cancer, or if your symptoms onset after the age of 45 – 50 years old, your physician may order further tests. They may include blood, stool, and imaging (colonoscopy with biopsies, sigmoidoscopy with biopsies.
How is IBS-M Treated?
Often diet and lifestyle changes can have a huge impact on gut health. Getting exercise and participating in managing stress through activities such as yoga or meditation can have a huge impact on a patient’s quality of life.
Many IBS patients of all types have benefited from experimenting with a low FODMAP diet. The low FODMAP diet is one of the most well-researched diets that shows significant symptom improvement for ~50-80% of those with IBS. 1 FODMAPs are types of carbohydrates that are either poorly absorbed in the intestine, or that ferment in the gut, leading to digestive distress. It involves significantly reducing intake of these carbohydrates for a short period of time, followed by strategic reintroduction to see which FODMAPs trigger which IBS symptoms. If you are thinking of trying this elimination diet, CDHF recommends working alongside a registered dietitian to help you guide you through it.
Your doctor may also recommend prescription or over the counter products if your IBS symptoms are severe and if lifestyle and dietary strategies have not helped. Typically, medications are targeted at the dominant symptom – diarrhea, constipation or pain.
- Antispasmodic medications may help reduce muscle spasms, abdominal pain and cramping.
- Antidepressant medications, in low doses, act on the chemical messengers in the digestive tract and can help relieve diarrhea, pain and cramping. In higher doses, these medications help to relieve depression and anxiety that may accompany IBS.
- Antidiarrheal medications, such as Loperamide, can help control diarrhea by reducing stool frequency and slowing the movement of the intestines.
- Laxatives speed up the motion of stool through the intestines and may be prescribed for people who have IBS with constipation. Laxatives are available in prescription or over-the-counter formulations. Speak to your doctor about which one is best for you.
- Prosecretory and analgesic agents, which increase the amount of fluid in the digestive tract as well as reduce the sensitivity of pain nerves in the intestines. They have been shown to soften bowel movements and make them occur more often, reduce the amount of bloating and to decrease abdominal pain in patients with IBS.
Over the Counter (OTC) therapies are also available such as peppermint oil capsules, probiotics, and fibre, among other ways to manage your IBS.
Looking for a way to track your IBS symptoms? Download CDHF’s myIBS app. The app allows you to digitally journal your symptoms, poop, food, sleep, stress and more, to help you better understand and manage your IBS.
This resource was made possible due to an unrestricted educational grant from Nestle Health Science, makers of IBgard.
References:
- Altobelli, E., Del Negro, V., Angeletti, P. M., & Latella, G. (2017). Low-FODMAP Diet Improves Irritable Bowel Syndrome Symptoms: A Meta-Analysis. Nutrients, 9(9), 940. https://doi.org/10.3390/nu9090940