Here are the basics about each of the medicines below. Only the most common reactions are listed. Ask your doctor if you need to take any special steps. Use each of these as advised by your doctor or the booklet they came with. If you have any questions, call your doctor.

Medicines are used to treat certain problems. There are many types that may be helpful. Some may be used in combination with one another.

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 the digestive system 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
  • Problems seeing
  • Problems having sex
  • Sleepiness
  • Confusion
  • Itching
  • Rash
Antidiarrheals

Common names:

  • Loperamide
  • Eluxadoline

These slow intestinal activity to ease diarrhea problems.

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

Common name: Lubiprostone

This medicine may help those who have constipation as their main problem, but haven't had success 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 plants that cannot be digested. They help the intestines work better. Slowly increase your fiber intake. Be sure to drink plenty of water when take it. Some types of fiber work better than others. Your doctor will help you find the one that will be most helpful.

Some problems are:

  • Bloating
  • Gas
  • Flatulence
Antidiarrheals

Common names:

  • 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

This will keep gas from getting into the intestines. It breaks up gas bubbles in the stomach, making it easier for it to bring up.

Some problems are:

  • Diarrhea
  • Nausea or vomiting
Probiotics

Common names:

  • Acidophilus
  • Bifidobacterium
  • Lactobacillus
  • Esherichia coli
  • Saccharomyces boulardii

Probiotics are healthy bacteria. They can be found is 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

If you are taking medicine:

  • Take medicine as directed. Do not change the amount or the 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.
  • Medicine can be dangerous when mixed. Talk to your doctor or pharmacist if you are taking more than one medicine. This includes over-the-counter products and supplements.
  • Plan for refills as needed.

Revision Information

  • Reviewer: EBSCO Medical Review Board Daus Mahnke, MD
  • Review Date: 12/2018 -
  • Update Date: 06/07/2019 -