You loved my destigmatizing IBS-C medication series so much that I’ve created an IBS-D (diarrhea series!) ⁠

There 6 medications that we will be talking about that exist to manage IBS-D.⁠

As a reminder – your doctor and pharmacist is the only person that can provide individual medication advice. The purpose of this post is to inform and educate, and most importantly – destigmatize!⁠

1. Fibre

OK let’s start with fibre – which is a great ‘non-pharmacological’ option we use like a medication – with the right dosing and timing.⁠

Many times, when I see patients for IBS-D, they’ve been told to reduce their fibre. Certain types of fibre can, in fact exacerbate diarrhea, however – certain types of fibre, in the right doses have actually been shown to benefit diarrhea too! ⁠

Patients are SHOCKED when I suggest psyllium for diarrhea, and often say ‘I thought that was for constipation!’.⁠

Some fibres are like the ‘great regulator’. They help bring bowels to a middle ground, and can improve both constipation and diarrhea. Pretty cool right? ⁠

Most fibres that benefit diarrhea are soluble. Meaning they act like a sponge to suck up extra water – improving stool consistency, frequency, and urgency/incontinence.⁠

A few of these include:

  • psyllium⁠
  • partially hydrolyzed guar gum (PHGG)⁠
  • methylcellulose⁠
  • wheat dextrin⁠
  • banana flakes (banatrol)⁠

I’m impartial to psyllium, as I used it a TON really effectively when I worked in oncology, and PHGG is new-to-the-scene but has also been a fan favourite in my practice for dissolving clear! ⁠

Sometimes, dissolving the fibre supplement in a bit less water, if diarrhea is really significant can be helpful so the ‘gelling’ action takes place in the bowels. ⁠

Have you used fibre strategically to manage IBS-D before?

2. Bismuth Subsalicylate and Attapulgite

⁠⁠Bismuth subsalicylate (pepto, more common) and attapulgite (less frequently used) are two over the counter meds used for occasional diarrhea. ⁠⁠
Bismuth has far more evidence for the use of occasional diarrhea by helping reabsorb fluid, yet I often see patients not consider these as ‘tools’ in their IBS-D toolkit.⁠⁠
Meant for occasional use, these medications can help in situations when diarrhea in flux is impacting your ability to do the things you love (or even just leave the house!)

Examples include:⁠⁠

  • nervous poops exacerbating your IBS-D⁠⁠
  • travel – especially if what you typically eat changes⁠⁠
  • long drives or flights – when bathrooms can’t be close by or easily accessible⁠⁠

⁠⁠What about regular use?⁠⁠

In more recent studies, researchers have looked at the daily use of bismuth to manage IBS-D, and found it to be successful, however the studies were relatively small. Given the favorable safety profile of bismuth – it holds promise as one potential option for patients, but more research is needed!⁠⁠

The Takeaway ⁠⁠

Discuss with your doctor, dietitian and pharmacist about having these on hand to help situationally and make sure that your IBS-D isn’t holding you back! If you have diarrhea more frequently, stay tuned as we de-stigmatize some of the other medications for IBS-D management!⁠⁠

3. Loperamide

⁠⁠Loperamide is an over the counter medication (better known as immodium) that slows the bowels down, improves water absorption and increases anal sphincter tone (trust me – an important factor if you’ve ever experienced fecal leakage or incontinence). ⁠⁠
It has a very favourable safety profile and has been shown to be extremely effective in reducing diarrhea, however, it does not improve pain or distension associated with IBS-D.⁠⁠
Typically loperamide is thought of for situational use – many patients might use it pre-emptively if they don’t want to get diarrhea (ie for a flight or long road trip), or they may use it as diarrhea onsets. Both options can be really helpful! ⁠⁠
However, many of my patients are nervous to use it too often or too much, and often will err on the side of NOT using it and suffering through diarrhea, over using it and having better control. This is where it’s important for patients to understand its safety and efficacy! ⁠⁠
There is a good body of evidence that shows loperamide is safe and effective with daily usage in IBS-D – however if you’re needing it regularly, or in increasing frequency without great improvement, it can be worth a discussion with your doctor to see if another options are better suited. (Especially if pain is a predominant feature in your IBS-D; there are medication management options that tackle both!) ⁠⁠
Stay tuned for our next part of the series on IBS-D meds!⁠⁠

4. Tricyclic Anti-Depressant

⁠⁠⁠⁠I’ve written before on how neuromodulators (used to be classified as anti-depressants/anti-anxiety meds) have a TON of stigma. In fact, a study showed 80% of those with IBS offered neuromodulators as a treatment option decline due to the stigma around mental health! (see that post in my stories).⁠⁠
To help reduce the stigma it’s important to understand why neuromodulators were reclassified.⁠⁠
Turns out, serotonin, dopamine, and/or norepinephrine don’t just impact your mood, but also significantly impact gut motility and function. In fact, about 80% of your serotonin is found in the gut, and it’s job is NOT to influence your mood, but rather, regulate how your gut moves & secretes things, gut pain, and gut immunity! ⁠⁠
TCA’s, tricyclic anti-depressants, basically work by increasing serotonin and norepinephrine by preventing its re-uptake into neurone in the gut.⁠⁠

At low doses in IBS-D, TCA’s help to:⁠⁠

  • slow the bowels down ⁠⁠
  • reduce pain⁠⁠

In addition, we now know that microbes in our gut influence serotonin, and it has been postulated that perhaps the gut microbiome drives some of the changes in IBS by way of that! (see stories for a post on that!). In the meantime, I hope this post reduced stigma around neuromodulators – they’re not because IBS is ‘all in your head’ a common misconception, rather, because of the important role our mood hormones play in digestion!⁠⁠

5. Eluxadoline

As a reminder – your doctor and pharmacist is the only person that can provide individual medication advice. The purpose of these posts is to inform and educate, and most importantly – de-stigmatize!⁠⁠⁠
Today we’re talking about a new generation IBS medication called eluxadoline. As a dietitian, I was super pumped when there were finally some new options for patients with IBS-D.⁠⁠
Sometimes we exhaust all nutrition and lifestyle options for managing diarrhea, but symptoms symptoms persist, so it’s nice to have more ‘tools’ in the toolkit for IBS management – because there are very few medications available in the management of IBS-D!⁠⁠
Similar to loperamide, it is an opioid receptor antagonist that reduces abdominal pain, stool frequency, and improves stool consistency. ⁠⁠
However, eluxadoline isn’t the best suited for all patients, it may not be appropriate for those without a gall bladder or history of alcoholism due to increased risk of pancreatitis & sphincter of Oddi syndrome. For the majority of individuals though, this medication has a favourable safety profile and can make a significant difference in symptoms when used appropriately!⁠⁠

6. Rifamaxin

While definitely not the first line of therapy, I would be remiss if I skipped over discussing for rifaximin in IBS-D.⁠

Rifaximin is a really unique antibiotic;

It is a broad-spectrum antimicrobial agent that is minimally absorbed, which means it targets the gastrointestinal tract (and predominantly the small bowel). Plus, it has a low risk of antibiotic resistance and low risk of adverse events. It is on the expensive side of medications, with benefits rarely covering it in Canada, and a treatment course cost of around $350 (I’ve heard astronomical costs in the US for this, too!) ⁠

While we don’t know exactly how it works in IBS-D, researchers believe that the rifaximin alters the small bowel microbiota and that this drives a positive change in symptoms. ⁠

In the research, trials have found that rifaximin can improve both abdominal pain and stool consistency, however, relapse of symptoms often occur and do require repeat treatments. While this is promising, many questions remain on the safety and efficacy of ongoing treatments past the 3 rounds of treatment the TARGET trials looked at. ⁠

Interestingly, in further research, hydrogen and methane breath testing with lactulose better predicted who would respond to rifaximin in IBS-D – pointing to SIBO as an underlying driver of some IBS-D cases, with possible options, like rifaximin for treatment.