Lifestyle | Health & Wellness

Medications for IBS

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Both prescription and over-the-counter medications can play a part in managing IBS; this article takes a look at both.

Your own doctor, dietitian or pharmacist is the best person to advise on what medications or supplements are right for your particular situation, but here is an overview so that you will be educated about what is currently available and often recommended for people with IBS.

Please note that this list is not exhaustive and will be kept updated once yearly.

A graphic of a human body with the intestinal system highlighted, next to a medication bottle with pills spilling out. Feature image for Medications for IBS
There are many different medications and supplements meant to help with IBS symptoms.

We are also not making any recommendations or providing medical advice. This is for information purposes only. Always work with your gastrointestinal medical team to determine what the most appropriate course of action is right for you.

Although Medications and Supplements can help manage IBS, it is important to note that all medications and supplements have side effects, and side effects can influence the gut both negatively or positively.

Medications Can Play A Role

Irritable bowel syndrome (IBS) is real. It hurts. It’s embarrassing. And it’s difficult to manage. IBS is what’s called a functional condition, meaning that the bowel by all evaluative means appears normal and healthy, but a person is experiencing symptoms of bloating, pain, wind and altered bowels for no apparent reason.

While there is no known cause nor cure for IBS, it can be well managed with a mix of strategies that address diet, stress and medications.

Let’s take a look at various medications, by type and some available options.


Fibers are some of the most commonly used options and increasing fiber is often considered “first line treatment” for IBS. Fibers work in a number of ways but improving laxation, optimizing stool form and improving gut transit time. They can be helpful for both constipation and diarrhea. Fiber supplements are suitable for long term use and many have the added benefit of having a positive effect on gut microbiome, cholesterol and stabilizing blood glucose levels. 

  • Kfibre /happiGut (FODMAP Friendly certified) is made from sugarcane (with the sucrose removed). Kfibre is backed by university research showing that it helps with regularity, constipation and dietary indigestion. While it is fermented, the fermentation is uniform to minimize gas and bloating. The other cool thing about Kfibre is that it is a complex fiber meaning it is not heat treated and retains the fibers and nutrients found naturally in whole fruits and veggies, which contribute to supporting gut health and microbiome. 
  • Bulk forming non fermentable fibers have gel forming properties that absorb water and make stool bulkier and softer. As they are non-fermentable they do not contribute to gas or bloating. Options include:
    • Normafibe /generic name stericulia
  • Bulk forming fermentable fibers are generally isolated soluble fibers that act like a sponge soaking up water in the digestive tract. This makes loose stools better formed and small hard stools bulkier and softer. Soluble fibers are generally well tolerated in IBS. Options include:
    • Sunfiber (Monash certified)/generic name PHGG (partially hydrolysed guar gum). Has been shown to be helpful for both constipation and diarrhea and appears well tolerated in IBS
    • Metamucil or Fybogel/generic name psyllium is generally well tolerated, however, some people do report increased bloating with it.
    • Fibercon/generic name polycarbophil
    • Benefiber/generic name wheat dextrin has not formally been studied in IBS. It is not suitable for those with celiac disease or a wheat allergy.


Osmotic Laxatives

These work by drawing water into the digestive tract and keeping it well lubricated so that stool can pass through more easily. Osmotic laxatives are generally very effective for constipation, particularly when combined with a fiber supplement and are considered suitable for long term use.

Options include:

  • Milk of Magnesia/generic magnesium
  • Miralax/generic name PEG (Polyethylene glycol)
  • Movicol or Osmolax/generic name macrogol
  • Lactulose 
  • Glycerin suppositories

Stimulant Laxatives

Stimulant laxatives work by stimulating the nerves in the gut and causing them to push matter through. These are very effective but are more likely to cause cramping and discomfort. Even though some of these are “plant based” or “natural”, there is some research that indicates that overuse of stimulant laxatives can be habit forming and result in dependence, so these are more often used for “situational” constipation rather than long term use. 

If you are requiring these on a more regular basis, this might be a sign it is time to review with your doctor and discuss other options. Like all medications and supplements, your own doctor can advise on what options and how often it is safe for you to use them. 

Options include:

  • Dulcolax, Fleet, Bisacolax, BisacEvac, Laxit, Modane, Codulax, Alophen/generic name bisacodyl
  • Senna
  • Cascara sagrada
  • Castor oil

Softeners or Emollient Laxatives

Stool softeners are kind of like moisturizer for your stool. They work by increasing the amount of moisture in your stool. These are not habit forming and are suitable for long term use, however, some people find them slightly less effective than other options. If these are working well for you, that’s great. If not, chat to your doctor about other options.

Options include:

  • Colace, DulcoEase, Silace, Soflax/generic name docusate
  • Coloxyl

Treatments for Diarrhea 


It works by blocking opioid receptors in the gut wall, reducing the contractions and slowing movement of matter through the gastrointestinal tract. This reduces the frequency of bowel movements and increases the time that the stool also stays in the intestine allowing more water to be absorbed by the large intestine, resulting in a “drier” stool. Loperamide is not recommended if you have blood in the stool, have a fever or antibiotic induced diarrhea. Although loperamide is safe to use, if you find you are needing it regularly, it’s a good idea to chat to your doctor to see if there is a better option.

  • Immodium, Gastro-Stop, Diamode, Imotil, Kao-Paverin, Dioraleze/generic name loperamide 

Viberzi/Generic name eluxadoline

Eluxadone is similar to loperamide and works by blocking opiod receptors in the gut wall to slow the gut. It has been shown to decrease abdominal pain, stool frequency and improve stool consistency. Unlike loperamide, eluxadoline is usually taken regularly rather than on an “as needed” basis.

Amitiza/Generic name lubiprostone

Lubiprostone works by increasing fluid secretion in the small intestine to help with constipation dominant IBS when diet and other treatments are not working. This medication may help with bloating, abdominal pain, improving stool form, reducing the need to strain and decreasing the feeling of incomplete evacuation. 

Lotronex/Generic name alosetron

Aloestron is prescribed for diarrhea dominant IBS in women. It works by relaxing the colon, slowing the movement of waste resulting in less watery and less frequent stools. It may also reduce abdominal pain and urgency. 


Lomotil reduces diarrhoea by slowing the contractions of the intestines. This slows the speed that matter moves through the intestines and results in a “drier” and less urgent stool.


Anticholinergics work by blocking receptors on nerve cells and reducing bowel spasms. They relax the smooth muscle and relieve pain associated with contractions in the gut. In some cases, they are recommended for bouts of diarrhea. These medications are generally safe but can cause constipation, dry mouth and blurred vision.

  • Buscopan/Levsin generic name hyoscine
  • Levbid extended-release hyoscine
  • Bentyl/generic name dicyclomine
  • Mebeverine
  • Donnatab


Simethicone is used to relieve painful pressure of excess gas and bloating in the stomach and intestines. It works by breaking up gas bubbles in the gut and making them easier to pass. There are multiple brand names for simethicone, some of the most common ones are:

  • DeGas
  • Alka-Seltzer
  • Biscarsim
  • Gas-X
  • Gasbusters
  • Dulcogas
  • Infacol

Peppermint Oil

Peppermint oil helps to relax smooth muscle and breaks up gas, making it easier to release. Research has shown it to reduce abdominal pain and improve global symptom’s scores including quality of life, satisfaction with bowel habits, distention and pain. Peppermint oil can be purchased in enteric coated capsules and most pharmacies and drug stores e.g. Mintec and IBGard. This coating ensures that it survives the stomach acid and the capsule makes it intake to the bowel where you want the peppermint oil to do its thing. Because peppermint relaxes smooth muscle, it can worsen reflux


Iberogast is one of the few herbal supplements that has some research behind it for helping with functional dyspepsia and IBS. Research has shown it to reduce total symptoms scores, improve abdominal pain and may improve gastric emptying. The taste can be “polarizing” but if you’re looking for a safe and natural approach, Iberogast may be for you. Iberogast appears to work best when taken regularly three times a day with meals. Iberogast has a distinctive taste and may not be to everyone’s preference.

Pepto-Bismol/Generic name bismuth subsalicylate

Pepto-Bismol works by protecting the stomach and digestive tract from stomach acid. It also has mild antacid effects. It is used to treat occasional stomach upset, heart burn, nausea and diarrhea. It may also be used to treat or prevent travellers’ diarrhea. In some cases, a doctor may prescribe it in combination with other medications to treat Helicobacter Pylori. Pepto Bismol is a salicylate. Salicylates are a plant chemical which some people are sensitive to and if so, may worsen IBS symptoms. 

Carafate (Sucraflate)

Is used to treat and prevent stomach ulcers by forming a protective coating over the ulcer to prevent further injury and allow healing. If you are taking other medications (including antacids), you may need to take them at a different time of the day to Carafate, so make sure to discuss this with your pharmacist. 


Antibiotics may be used to address a parasite, bacterial overgrowth (SIBO), helicobacter pylori (in combination with PPIs) or travellers’ diarrhea. Rifaxamin is the most common antibiotic used in IBS.  It’s a nonabsorbable antibiotic, so it targets the gastrointestinal tract (particularly the small intestine). While not well understood, it’s believed that Rifaxamin alters small bowel microbiota, resulting in positive changes in IBS symptoms. Unfortunately, the benefits appear to be transient and repeat treatment is often necessary. The most common antibiotics prescribed for IBS include:

  • Rifaxamin
  • Flagyl/generic name metronidazole
  • Ciprofloxin
  • Neomyacin
  • Biaxin/Generic name clarithromycin

Proton Pump Inhibitors (PPIs) 

PPIs are used to treat reflux. They work by reducing the production of stomach acid. They appear to work best when taken over time rather than just occasionally. While PPIs are safe for short term use, they carry side effects when used long term including increased risk of B12 deficiency, osteoporosis and Clostridium difficile (c.diff) infection. PPIs are often used in conjunction with antibiotics to treat helicobacter pylori. 

  • Nexium/generic name esomeprazole
  • Protonix/generic name pantoprazole
  • Prevacid/generic name lansoprazole
  • Prilosec/generic name omeprazole


Antacids can be used for immediate treatment of occasional reflux, heart burn or indigestion. If you find you are using this twice or more per week on a regular basis, it is worth discussing worth your doctor.

  • Tums/generic name active ingredient calcium carbonate
  • Quick-Eze/blend of calcium carbonate, magnesium carbonate, magnesium trisilicate
  • Pepcid/generic name famotidine
  • Zantac/generic name ranitidine – In April 2020 the FDA issued a recall of all forms of this heartburn drug because they may contain low levels of N-nitrosodimethylamine (NDMA), a substance that could cause cancer. If you take this drug, have been prescribed this drug, or have some in the medicine cabinet, please review with your doctor.
  • Zantac 360/generic name famotidine – Please note that the “Zantac” brand has re-launched as “Zantac 360”. Its new formulation contains famotidine, which does not have the same issues as ranitidine. If you are taking a “Zantac” product, please make sure it is the new formulation that contains famotidine.


Prokinetics help strengthen the sphincter between the esophagus and the and increase the speed of stomach emptying. They are commonly used for reflux, gastroparesis and nausea.

  • Metoclopramide
  • Domperidone
  • Prudac/generic name prucalopride
  • Bethanechol
  • Prepulsid, Propulsid/generic name cisapride

Cyclase-C Agonists

Linzess & Trulance

Linzess, generic name linaclotide, and Trulance, generic name plencanatide, belong to a class of drug called Guanylate cyclase-C agonists. These work by increasing the fluid secretion in the intestines, particularly the small intestine, which softens stools and stimulates a bowel movement. They are used to treat constipation irritable bowel syndrome. Linzess can cause diarrhea but taking it with food may reduce this.


Antidepressants and Anti-anxiety Medications

Neuromodulators are used to treat depression and in small doses appear to be very effective for reducing the sensitivity of gut nerves as well as the relaxing effects they have on the head brain. These types of medications usually take a few weeks to have peek effect and usually require a weaning off period when you are ready to stop them. While they may not be the right fit for everyone, in some people they can be very effective.

  • Endep/generic name amitriptyline
  • Tofranil/generic name imipramine
  • Norpramin/generic name desipramine
  • Pamelor/generic name nortriptyline
  • Celexa/generic name citalopram
  • Prozac/generic name fluoxetine
  • Paxil/generic name paroxetine
  • Zoloft/generic name sertraline

Pain Medications

Medications for chronic pain have been shown in a few small trials to ease severe pain and bloating associated with IBS. Given the limited evidence for these, it is suggested beneficial to trail better studied medication, lifestyle and dietary measures first.

  • Lyrica/generic name pregabalin
  • Neurontin/generic name gabapentin

Bile Acid Binders 

Bile acids are usually secreted into the GI tract to help with breaking down fats and then reabsorbed at the end of the small intestine. If the bile is not reabsorbed properly, it then travels into the colon and can result is loose and watery stools. If this excess bile acid is the cause of the diarrhea, bile acid binders can be very effective for achieving more formed and less frequent stools. Your doctor can perform a blood or stool test or may assess your symptoms clinically to determine if this is relevant to you. Bile acid binders may also be used to treat high cholesterol.

  • Questran/generic name cholestyramine
  • Cholestid/generic name colestipol
  • Cholestagel/generic name colesevelam

The Takeaway

While this list of medications is extensive, it is not complete. There are many options for treating and managing your IBS depending on your sensitivities and the underlying causes. We are not making a recommendation for any of the products on this list – nor providing medical advice. The best person to discuss your medication and supplement needs with is your doctor, dietitian or pharmacist who can provide individualized advice for your situation. 

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