- Antispasmodics–IBS drugs like Levsin and Bentyl prevent the muscle inside of the intestines from going into spasm. They have been shown to decrease pain in some studies with IBS, but have lots of side effects and are not an option I use commonly.
- Fibre formers or ‘bulking’ agents such as Psylliym fibre. They work by increasing the bulky stuff within the intestines so that stool is moved quicker through the gut. It can sometimes improves constipation symptoms of IBS.
- Osmotic Laxitives, such as PEG 3350. This is a powder you mix into juice or water and it helps constipation symptoms of IBS by putting more water into the gut. They are NOT habit forming and seem safe, but haven’t been studied long term.
- Immodium, an ANTI diarrhoea IBS drug used for diarrhea symptoms of IBS.
- SSRI Anti depressants (ie. such as Paxil). These have been shown to lead to ‘improved feeling of wellbeing’ in some studies but have not shown to have a great benefit on the GI (gastrointestinal) symptoms of diarrhea, constipation, bloating.
- Zelnorm or Tegaserod. This is a Serotonin Receptor Agonist and works on special receptors for serotonin in the gut wall, and can improve constipation. It also has side effects, some potentially life-threatening and I don’t think the benefits outweigh the risks in most cases–AVOID.
Lotronex (Alosetron). This IBS drug does the opposite of number 3–it is a Serotonin ANTAGONIST and is used in people who have lots of diarrhea with their IBS symptoms. However, it also has been linked with toxic side effects, some of which are serious and I would AVOID this one too.
However, there are some medications (“IBS drugs’) that doctors prescribe for IBS, so here is a brief explanation of them: