Irritable bowel syndrome (IBS) treatment focuses on relieving symptoms to help you feel better. Many people use over-the-counter (OTC) drugs, prescription medications, or both to relieve IBS symptoms. Eating certain foods and speaking with a mental health professional can also help.
Some medications may cause side effects or come with risks, so it’s important to speak with a doctor before taking any new medication.
Hyoscyamine

Hyoscyamine slows movement in your intestines and stomach. It also reduces how much stomach acid and other fluids your body makes.
This medication is available with a prescription in a tablet or liquid to take three or four times a day. Some people prefer the extended-release version, which you take twice a day.
If you take an antacid, hyoscyamine won’t work as well. You can look at the directions on the package or ask the pharmacist when to take hyoscyamine if you take other medications.
There are many brand names for hyoscyamine:
Note that hyoscyamine is not currently approved by the Food and Drug Administration (FDA). It’s advisable to talk with a doctor before taking this medication.
You may have some side effects while taking hyoscyamine, such as:
- drowsiness
- dizziness, headache, or lightheadedness
- feeling flush
- blurry vision
- light sensitivity
Some side effects may affect your digestive system, leading to:
- constipation
- dry mouth
- difficulty urinating
The more serious side effects include:
- diarrhea
- skin rash
- eye pain
- an irregular or fast heart rate
If you need help covering the cost of medications, Optum Perks free Discount Card could help you save up to 80% on prescription drugs. Follow the links on drug names for savings on that medication, or search for a specific drug here.
Diphenoxylate atropine
Diphenoxylate atropine is sold under the brand name Lomotil. This combination drug contains two medications:
- diphenoxylate to treat diarrhea
- atropine to cause side effects to prevent people from taking too much of the medication
You may take diphenoxylate atropine while taking other steps to treat diarrhea, like staying hydrated, eating bland foods, and replacing electrolytes.
You can take Lomotil four times per day as a pill or liquid, and most people feel better within 48 hours. If you don’t feel better within 10 days, you can stop taking the medication and talk with a doctor.
Lomotil can become habit-forming, so it’s important to only take as much as your doctor prescribes. They may recommend taking less when your IBS symptoms get better.
Common side effects of Lomotil include:
- headache
- restlessness
- tiredness
- confusion
- mood changes
Some of the side effects may affect your digestive system, leading to:
- stomach discomfort
- nausea
- vomiting
- loss of appetite
There are also more serious possible side effects that require emergency medical attention. Call 911 or your doctor if you experience:
- hallucinations or hearing voices
- numbness in your legs or arms
- ongoing stomach pain
- stomach bloating
- shortness of breath
- problems breathing or swallowing
- hoarse voice
- hives, rash, or itching
- swelling
Lomotil is a controlled substance. A doctor may only be able to fill a certain number of prescriptions for the drug. It’s important to follow the doctor’s advice on dosage and reach out if you experience serious side effects.