Here are the basics about each of the medicines below. Only the most common problems are listed. Use each of these as advised by your doctor or the booklet they came with. Call your care team with any questions.

Medicines are used to treat certain problems. There are many types that may be helpful. Some may be used with others.

Prescription Medicines

Antispasmodics

  • Dicyclomine
  • Hyoscyamine
  • Cimetropium—not available in the US

Antidiarrheals

  • Loperamide
  • Eluxadoline

Antidepressants

  • Amitriptyline
  • Paroxetine

5-hydroxytryptamine (5-HT) Antagonists and Agonists

  • Alosetron

Antibiotics

  • Rifaximin
  • Neomycin

Other Medicines

  • Lubiprostone

Prescription Medicines

 

Antispasmodics

Common names:

  • Dicyclomine
  • Hyoscyamine
  • Cimetropium—not available in the US

These may quiet digestion and ease painful bowel spasms. Problems with these are mild when taken as advised.

Some problems are:

  • Dry mouth
  • Nausea
  • Lightheadedness
  • Vomiting
  • Changes in heart rate
  • Problems passing urine
  • Eyesight problems
  • Problems having sex
  • Sleepiness
  • Confusion
  • Itching
  • Rash
 

Antidiarrheals

Common names are:

  • Loperamide
  • Eluxadoline

These slow the intestines to ease diarrhea.

Some problems are:

  • Dry mouth
  • Nausea or vomiting
  • Bloating or gas
  • Rash
  • Allergic reactions
  • Sleepiness
  • Confusion
  • Lightheadedness
  • Euphoria
  • Drowsiness
 

Antidepressants

Common names:

  • Amitriptyline
  • Paroxetine

Some antidepressants may ease intestinal spasms. They can be used in those who have depression linked to IBS.

Some problems are:

  • Dry mouth
  • Nausea
  • Lightheadedness
  • Sleep problems
  • Diarrhea
  • Sleepiness
  • Anxiety
  • Weight loss or weight gain
  • Problems having sex
 

5-hydroxytryptamine (5-HT) Antagonists and Agonist

Common name: Alosetron

Alosetron is used to treat diarrhea. It can also help with other IBS problems, such as belly pain.

Some problems are:

  • Severe constipation
  • Nausea or vomiting
  • Belly pain
 

Antibiotics

Common names:

  • Rifaximin
  • Neomycin

Antibiotics may be used to treat IBS problems, such as bloating and diarrhea.

Some problems are:

  • Nausea or vomiting
  • Belly pain
  • Feeling tired
  • Headache
  • Lightheadedness
 

Miscellaneous Medicines

Common name: Lubiprostone

This medicine may help people who have constipation but have not been helped by using fiber.

Some problems are:

  • Nausea or vomiting
  • Headache
  • Belly pain
  • Heartburn
  • Diarrhea

Common name: Linaclotide

May be used to increase the amount of fluid in the bowel.

Some problems are:

  • Diarrhea
  • Gas
  • Belly pain

Over the Counter Medicines

 

Fiber Supplements

Common names:

  • Psyllium
  • Bran
  • Polycarbophil
  • Methylcellulose

Fiber comes from the woody parts of plants and seeds that we cannot digest. It helps the intestines work better. Slowly increase your fiber intake. Be sure to drink plenty of water when taking it. Some types of fiber work better than others. Your doctor will help you find the one that is right for you.

Some problems are:

  • Bloating
  • Gas
  • Flatulence
 

Antidiarrheals

Common names are:

  • Loperamide—May cause constipation.
  • Lomotil
  • Bismuth subsalicylate—Soothes the digestive tract without causing constipation. But, it can cause dark stools and a dark tongue.
 

Anti-gas

Common name: Simethicone

Simethicone helps break up big gas bubbles into smaller gas bubbles. These can pass more easily without stretching the bowel wall as much. Cramps are often due to bowel wall stretching.

Some problems are:

  • Diarrhea
  • Nausea or vomiting
 

Probiotics

Common names are:

  • Acidophilus
  • Bifidobacterium
  • Lactobacillus
  • Escherichia coli
  • Saccharomyces boulardii

Probiotics are healthy bacteria. They can be found in foods like yogurt or taken as a supplement. A blend may be more helpful than just one. Some have found that probiotics help ease belly pain and other problems of IBS. Talk to your doctor about adding probiotics to your diet.

Gas and bloating are the most common problems. It is often mild and does not last long.

 

Pain Relievers

Common name: Acetaminophen

Acetaminophen may ease belly pain.

Some problems are:

  • Itching
  • Headache
  • Sleepiness

Special Considerations

When taking medicine:

  • Take your medicine as advised. Do not change the amount or schedule.
  • Be aware of the side effects of your medicine. Tell your doctor if you have any.
  • Talk to your doctor before you stop taking any prescription medicine.
  • Do not share your prescription medicine.
  • Medicines can be harmful when mixed. Talk to your doctor or pharmacist if you are taking more than one, including over the counter products and supplements.
  • Plan for refills.
REFERENCES:

Ford AC, Lacy BE, Talley NJ. Irritable bowel syndrome. N Engl J Med. 2017;376(26):2566-2578.

Irritable bowel syndrome (IBS). EBSCO DynaMed website. Available at:http://www.dynamed.com/topics/dmp~AN~T113627/Irritable-bowel-syndrome-IBS. Updated September 10, 2018. Accessed August 15, 2019.

Irritable bowel syndrome (IBS). Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/gastrointestinal-disorders/irritable-bowel-syndrome-ibs/irritable-bowel-syndrome-ibs. Updated April 2019. Accessed August 15, 2019.

Probiotics for irritable bowel syndrome. EBSCO DynaMed website. Available at:http://www.dynamed.com/topics/dmp~AN~T474265/Probiotics-for-irritable-bowel-syndrome. Updated August 11, 2017. Accessed August 15, 2019.

Last reviewed August 2019 by EBSCO Medical Review Board James P. Cornell, MD  Last Updated: 8/15/2019