Linzess vs. Amitiza: Comparing Constipation Medications

Authored by The Rx Advocates, / Medically Reviewed by Dr. Conor Sheehy, PharmD, BCPS


Linzess and Amitiza are two medications used to treat irritable bowel syndrome with constipation (IBS-C) and Chronic Idiopathic Constipation (CIC).

Irritable Bowel Syndrome (IBS) is a digestive disorder. It is common, affecting 7-21% of people. Common symptoms can be abdominal bloating, discomfort, or pain, and changes in the frequency and appearance of bowel movements.

IBS-C is a form of IBS. The abdominal pain and discomfort happen with constipation. This is when you have a hard time passing stool. Signs of constipation are:

  • Having less than three bowel movements a week
  • Hard stools that are hard to pass
  • Bowel movements that feel incomplete

Signs of IBS-C are:

  • Abdominal pain and discomfort
  • Changes in bowel function
    • Straining
    • Infrequent stools
    • Hard or lumpy stools
    • Feeling as if the bowel is not empty
  • Bloating
  • Gas
  • Feeling as if there is a blockage that is keeping stools from passing; feeling like you need to press on your body or change position to help it out

CIC is chronic constipation with no known cause and pain is not as predominant or as frequent.

What is Linzess?

Linzess is an FDA-approved medication to treat digestive conditions in adults. The active ingredient is linaclotide. Specifically, it treats:

  • Irritable bowel syndrome with constipation: Constipation with bloating or abdominal pain
  • Chronic idiopathic constipation: Frequent constipation with no known reason

Linzess is a guanylate cyclase-C agonist. It increases the fluid in the intestines, and helps food move quicker through the digestive tract. This helps the bowels move more often, easing constipation. Linzess can also lessen the pain in the digestive system. It does this by reducing the contractions of muscles and relaxing the nerves.

Linzess does not have a generic form available.

The Side Effects of Linzess

Linzess can cause side effects. These can range from mild to severe. Your doctor will determine if this is safe for you and if the benefits outweigh the risks. If any of these become bothersome or last longer than expected, contact your doctor or pharmacist.

Common Side Effects

  • Belly pain
  • Gas
  • Diarrhea
  • Bloating

Mild Side Effects

  • Gastroesophageal reflux disease (GERD)
  • Headache
  • Upper respiratory infection
  • Mild diarrhea

Severe Side Effects

  • Allergic reaction
  • Severe diarrhea

What is Amitiza?

Amitiza is a digestive medication for adult women. It treats the following types of constipation:

  • Chronic idiopathic constipation (CIC)
  • Irritable bowel syndrome with constipation (IBS-C) in females
  • Opioid-induced constipation (OIC) in people who take opioids for chronic pain not related to cancer

Amitiza is a chloride channel activator. Chloride channels in your cells are proteins that carry molecules across cell membranes. This medicine increases the activity of these channels in your body’s cells. It is not a laxative, stool softener, or type of fiber. It works by increasing the amount of fluid in the intestines. This helps the stool to pass.

Amitiza’s active ingredient is lubiprostone. That is the name of its generic form that was FDA approved in 2008.

Side Effects of Amitiza

Here are the possible side effects of Amitiza:

  • Diarrhea
  • Nausea
  • Vomiting
  • Headache
  • Urinary tract infection
  • Gas or bloating
  • Stomach pain
  • Sinus infection
  • Tiredness
  • Difficulty breathing
  • Upper respiratory infection
  • Cold symptoms
  • Indigestion
  • Back or joint pain
  • Swelling in the hands or legs

Severe side effects:

  • Allergic reaction
  • Fainting
  • Low blood pressure
  • Severe diarrhea

Linzess and Amitiza Precautions

You should know of any precautions before starting a new medication. Your doctor should be aware of your history but it is important to discuss all of this with your healthcare provider. They will weigh the benefits and risks to determine what is best for you. These are the things you should know before taking Linzess or Amitiza.


  • Allergies: Tell your doctor about any allergies you have to medications, food, preservatives, dyes, animals, etc.
  • Pediatric: This product should NOT be used in children younger than 2 years old. It can cause increased dry mouth and can lead to dehydration.
  • Drug interactions:
    • Any medications that can cause nausea. This can increase the risk of nausea if taken with this medicine.
    • Anti-diarrheal medications: This can cause diarrhea. Use caution when taking an anti-diarrheal.
  • Other medical problems: Tell your doctor if you have a history of or currently have a stomach or bowel blockage.


  • Allergies: Your doctor needs to know about any allergies you have, especially to any medications.
  • Drug interactions:
    • Anti-diarrheal medications: This can cause diarrhea. Use caution when taking an anti-diarrheal.
    • Other medications that may cause nausea can increase the risk of nausea if taken with this medicine.
  • Other medical conditions: Tell your doctor if you have the following:
    • Known or suspected blockage in the stomach or bowel
    • Diarrhea (severe)
    • Liver disease (moderate to severe)

Linzess vs. Amitiza: A Comparison

These medications are two good options for treating IBS-C/CIC. There are some similarities and some differences between the two.


  • They both promote increased fluid to make passing stool easier.
  • They have similar side effects.


  • Amitiza is only indicated in women over 18 years old. Linzess is approved for all adults.
  • Amitiza treats opioid-induced constipation.
  • A one-month supply cost:
    • Linzess: About $430
    • Amitiza: About $288
  • Linzess should be taken on an empty stomach. Amitiza should be taken with food.

Is One Better Than the Other?

No. They both work well at relieving constipation. These work better than stool softeners, osmotic laxatives, or stimulant laxatives. Your doctor will look at various factors when determining which medicine to prescribe for you.

How Can The Rx Advocates Help People Save Money on Their Monthly Prescriptions?

Constipation is not a comfortable situation for anyone. For someone with IBS-C or CIC, it is agonizing. Medication is necessary to help get their system moving in the right direction. Over-the-counter medicine is available, sure. But, that is not as effective as a prescription medication, specially formulated to do what is needed.

If this is you, your doctor knows that Linzess or Amitiza could be the answer. He knows what will work best when you just can’t poop.

But even with insurance, these medications could be expensive. Sometimes, insurance won’t approve them.

Let us help you.

Here at The Rx Advocates, we have seen how difficult it is for people to pay for their medications. In our current economic society, people are having to choose between monthly medications and food for their families. This should not have to happen!

We help people save money every month on their Linzess and Amitiza prescriptions. With our prescription assistance program, you can get discounts on many different kinds of medications.

You pay for our service and your medicine cost. Your medicine is delivered to your house at no additional charge.

If you need help with affording your IBS-C medication, we want to talk to you. Don’t hesitate – please contact us today.

  1. Linzess. #1 Prescribed IBS-C/CIC Branded Treatment. September 2022. Available at:
  2. Amitiza. December 13, 2021. Available at:
  3. American Society for Gastrointestinal Endoscopy. Understanding Irritable Bowel Syndrome with Constipation (IBS-C). September 2022. Available at:
  4. Medical News Today. Linzess (linaclotide). April 14, 2022. Available at:
  5. Healthline. Side Effects of Linzess: What You Need to Know. June 12, 2022. Available at:
  6. Medical News Today. Amitiza (lubiprostone). September 1, 2022. Available at:
  7. Verywell Health. Amitiza (Lubiprostone) – Oral. December 1, 2021. Available at:
  8. Lubiprostone. October 19, 2021. Available at:
  9. Mayo Clinic. Linaclotide (Oral Route). February 1, 2022. Available at:
  10. Mayo Clinic. Lubiprostone (Oral Route). February 1, 2022. Available at:
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