Crohn's disease is a condition that causes inflammation and irritation in your digestive tract. It is a kind of inflammatory bowel disease (IBD). Common symptoms include diarrhea, pain in your abdominal (belly) region, rectal bleeding, and weight loss.
There is no cure for Crohn's disease, but many treatments are available to help address your symptoms. Medications range from steroids to anti-inflammatory drugs and antibiotics, depending on your symptoms.
Your doctor may also recommend nutrition plans, and even surgery in the case of complications.
Depending on which treatment options you choose, you may also have side effects. Side effects vary by medication, but some common ones include headaches, an upset stomach, and fatigue.
Pay attention to your symptoms over time and note how bad they are.
"I generally advise people to go on their gut instinct, excuse the pun. If it's something you've never had before, and you're on the drug recently, it's probably related," says Alan Moss, MD, chief scientific officer at the Crohn's & Colitis Foundation.
Types of Crohn's Disease Medications
There are a variety of medications to treat Crohn's disease. They include:
Aminosalicylates (5-ASA drugs)
Aminosalicylates are anti-inflammatory medications. They are often used to treat ulcerative colitis, another common form of IBD. Benefits to people with Crohn's disease are limited.
Corticosteroids
Steroids offer short-term reduction in inflammation. They may be used to treat symptom flare-ups in Crohn's disease but aren't typically used as a long-term treatment option.
Immunomodulators
Immunomodulators are drugs that alter your immune system in some way. Immunosuppressants are a type of immunomodulator that relax the way your immune system responds to perceived threats. Some common drugs for Crohn's disease in this category include azathioprine (Azasan Imuran) and methotrexate (Rheumatrex, Trexall).
Most Common Side Effects of Crohn's Medications
Side effects of treatments for Crohn's disease vary by medication. But some side effects are common across a number of available medications for Crohn's disease.
Pay attention to new symptoms that show up after starting a medication.
"The thing to look at is something that's new and beyond the scope of what they typically experience with their flare-ups," Moss says.
Headache
Most medications for Crohn's disease include some level of increased risk of headaches. Tension headaches are the most common form in people living with Crohn's disease.
But people with Crohn's disease may also have headaches more often for other reasons linked to the condition. Vitamin deficiencies, infection, and abnormal immune responses that come with Crohn's can all contribute.
If you get a tension headache, first rest, use an ice pack, or take a hot shower to relieve symptoms. If your headaches persist, there are plenty of medications available. Acupuncture, massage, and deep breathing techniques also offer benefits.
Nausea
Treatments for Crohn's disease of all kinds may include a side effect of nausea. Nausea can also be a symptom of Crohn's disease. It's important to see your doctor to find the potential cause.
Nausea can make you not want to eat regular meals and lead to a loss of appetite or weight loss.
If you feel a surge of nausea come on, try to update your meal routine. Instead of eating three larger meals, try for several smaller meals with snack breaks in between.
Remember to eat slowly. Focus on simple foods that don't have a lot of spice, fat, or sugar. Drink beverages at least 30 minutes before a meal. Don't drink alcohol, which could further upset your stomach.
You can rest after your meal, but try not to lie down for at least an hour afterward. You might want to rinse your mouth out to keep any unpleasant tastes from sticking around. You can also open windows to release any strong food odors.
Fatigue
Fatigue is a common symptom of Crohn's disease. It affects most people living with the disease.
Fatigue can also be a side effect of some biologics, like vedolizumab (Entyvio), and immunomodulators, like methotrexate. You may also have fatigue if you suddenly stop taking steroids after a Crohn's flare-up.
If you notice regular bouts of fatigue, talk to your doctor. You may want to have bloodwork done to find out if iron or vitamin deficiencies are adding to your tiredness. Check your current medications as well. Fatigue may be a side effect.
Try to manage stress to help fight fatigue. Exercise regularly, and practice mindfulness exercises. Check your sleep routine and update as needed to promote relaxation before bed.
Bloating
The 5-ASA drug olsalazine (Dipentum) includes a side effect of bloating. Crohn's disease itself can also cause a sensation of lowered appetite.
Feeling bloated can lead to a loss of appetite and potential weight loss.
If you feel bloated, over-the-counter medications can help relieve symptoms.
You might also consider eating smaller, more frequent meals. Remember to eat slowly and thoroughly chew food. Avoid eating dinner too late at night.
Some foods like beans, onions, and whole grains produce more gas that can cause bloating. Cook your vegetables to make them easier to digest.
You may be more likely to be lactose intolerant if you have Crohn's disease. Lactose intolerance can cause more gas production. You can also try eliminating other foods you suspect trigger bloating.
Don't forget to exercise, which helps promote digestion. Try not to sit for long periods.
Appetite and weight changes
Weight loss and a reduced appetite are both common symptoms of Crohn's disease.
Treatments you take for Crohn's disease may also cause changes in your appetite or weight. Some 5-ASA drugs, antibiotics, and immunomodulators can lead to a loss of appetite. If you stop taking steroids suddenly, it can lead to a decreased appetite as well.
Certain drugs can also lead to weight gain or loss. The immunomodulator treatment mercaptopurine (Purinethol) includes a side effect of weight loss.
Some biologics like certolizumab pegol (Cimzia) may contribute to weight gain. If you stay on certain steroids for a long time, like budesonide (Entocort EC, Uceris), you may notice weight gain as well.
A healthy weight and eating routine helps you maintain energy throughout the day and keep your condition under control.
If you struggle to maintain a healthy appetite, focus on eating smaller, more frequent meals to maintain energy levels and reduce bloating. Plan nutritious meals with ingredients you enjoy. If foods at certain temperatures cause you nausea, try changing it up and see if it helps your stomach.
Don't forget to stay hydrated throughout the day.
To keep a healthy weight, consider eating small, frequent, nutrient-dense meals and snacks. Consider adding in ingredients like nuts, fruit, yogurt, hummus, and avocados.
Avoid following restrictive diets unless you are working closely with a dietitian or doctor. Restricting yourself can lead to nutrient deficiencies and unplanned weight loss.
Increased risk of infection
You may have a higher risk of infection if you take certain treatments for Crohn's disease.
For example, many immunomodulators and biologics can make you more vulnerable to infection in your lungs and upper respiratory system. The corticosteroid budesonide includes a side effect of respiratory infection. The JAK inhibitor tofacitinib (Xeljanz) includes a side effect of upper respiratory infection.
Make sure to stay up to date on vaccines your doctor recommends to help prevent serious infections.
Wash your hands regularly. Avoid contact with people who are sick. Plan ahead before travelling internationally.
If you get an infection and notice severe symptoms, call your doctor right away.
Liver and kidney issues
Some Crohn's drugs could impact your liver and kidneys. Your liver is vital for everything from filtering your blood to fighting infections. The kidneys also filter your blood and remove waste from your body.
Immunomodulators may cause liver irritation. Some biologics can, in rare cases, lead to liver problems.
The immunomodulating drugs cyclosporine (Gengraf, Neoral, Sandimmune) and tacrolimus (Prograf) include a side effect of increased risk of kidney dysfunction. The 5-ASA drug balsalazide (Colazal, Giazo) has listed rare reports of kidney toxicity associated with the medication.
In severe cases of Crohn's disease, you may have kidney stones or inflammation in the liver as symptoms of the condition.
Liver damage can be reversible, but a small percentage of Crohn's patients get severe liver disease. Liver issues may not have obvious symptoms, or they may simply show up as lower energy levels.
Severe kidney issues are very uncommon, but conditions like kidney stones may show up more often. Kidney stones can come with symptoms like pain, nausea and vomiting, and blood in your urine.
If you notice unusual symptoms, consult your doctor right away.
5-ASA Side Effects
Diarrhea
Diarrhea is an uncommon side effect of 5-ASA drugs, but it can occur. It may be hard to know whether diarrhea is a result of the 5-ASA drug or a symptom of your Crohn's disease. Diarrhea is one of the most common symptoms of Crohn's disease.
Pay attention to any new symptoms soon after starting a new medication, and consult your doctor about them. It is important to find the reason for your diarrhea in order to treat it correctly.
To ease bouts of diarrhea, consider eating small, more frequent meals. Foods high in potassium or sodium can help control loose stools. Bananas, rice, and broth can be good choices.
If your diarrhea doesn't go away, talk to your doctor about trying the BRAT (bananas, rice, applesauce, toast) diet. Certain medications may also help ease symptoms. Make sure to stay hydrated with water and electrolytes.
Abdominal (belly) pain and cramping
Abdominal pain and stomach cramps are common symptoms of Crohn's disease. They can also be side effects of 5-ASA medications.
If you notice pain or cramping in your stomach, you have options. Certain medications may offer targeted pain relief for abdominal pain. Mindfulness exercises and therapeutic interventions may also help address chronic pain.
Pay attention to your diet. Some foods are more likely to trigger pain and cramping in your abdomen. Keep a food diary to track what you eat and how you feel.
Rashes
Some people develop a rash after taking a 5-ASA treatment. A rash is usually a sign of a minor allergic reaction to the medication, and it may come with a fever and itchiness.
If you notice a rash, tell your doctor right away. Symptoms typically stop once you stop taking the drug.
Side Effects of Corticosteroids
Weight gain
Weight gain is a very common side effect of steroids, especially if taken long-term or in a high dose. Steroids suppress the immune system and also change the body's chemistry. This can lead to changes in how much fluid your body retains, increases in your appetite, and also increased deposits of fat in certain parts of the body.
If you only take a small dose of a steroid or use it short-term, you probably won't see a significant increase in weight.
If you gain weight while on a steroid treatment, do not stop treatment. Stopping a steroid too quickly can cause other, more serious medical problems. Talk to your doctor about your options and how to manage weight increases while on treatment.
You may need to wait several months after finishing a steroid treatment before successfully shedding pounds. Meanwhile, focus on getting exercise and eating a nutritious diet. Stay hydrated with water.
If you feel more hungry than usual while on a steroid treatment, eat healthy snacks rich in protein and fiber. You may consider eating a number of smaller meals throughout the day, rather than three big ones.
Acne
If you use a steroid treatment in a moderate or high dose for many weeks, you may develop acne as a side effect. Steroid-related acne most often shows up in the chest region, but you may also notice it on other parts of your body.
The steroid may trigger acne in areas you already tend to get it, like on the face. The acne may not go away until you stop taking the steroid.
Talk to your doctor about medication options for severe cases of steroid-related acne.
Mood swings
If you take a steroid medication by mouth, you may notice mood swings as a side effect. Symptoms may also include changes in behavior and confusion.
If you notice significant mood changes after taking an oral steroid, talk to your doctor. You may be able to switch to a different steroid treatment.
Increased appetite
Steroids are well-known for making you feel more hungry than normal. This may contribute to weight gain.
If you notice your appetite increase dramatically, focus on eating nutritious, balanced meals. Monitor portion sizes. Talk to your doctor about whether any special dietary tweaks may help you.
Insomnia
Steroids can make it harder to fall asleep, especially if you receive a dose close to bedtime.
Ask your doctor to give you the steroid treatment in the morning, if possible, to allow enough time for your body to process the drug throughout the day.
Sleep problems are common among people living with Crohn's disease. If you have frequent insomnia, talk to your doctor about ways to improve your sleep quality.
Osteoporosis
Taking steroids can lead to osteoporosis over time. That's because steroids can make your body less able to absorb calcium and also speed up your body's process for breaking down bones.
Your risk of developing osteoporosis increases the longer you take a steroid, and the higher the dose you take. People with Crohn's disease may also have a higher risk of osteoporosis due to other symptoms of the condition, like chronic inflammation.
If you plan on taking a steroid treatment over an extended period of time, ask your doctor to monitor your bone density levels for signs of osteoporosis.
To keep your bones strong, make sure you're getting enough calcium and vitamin D in your diet. You can get calcium through foods like milk, broccoli, and tofu.
Get regular exercise. Lifting weights and doing weight-bearing exercises like running, walking, and climbing stairs are especially good for strengthening your muscles and bones.
Quit smoking. Smoking can accelerate bone loss.
Diabetes
Steroids can cause your blood sugar levels to rise. In some people, that can lead to diabetes, especially if you were already at high risk for type 2 diabetes.
Symptoms of diabetes include a frequent urge to go to the bathroom, particularly in the evening; a high level of thirst; fatigue; and unintended weight loss.
Your steroid-induced diabetes may go away after you stop treatment with steroids. But some people will still have diabetes after stopping treatment.
You may not need to treat steroid-induced diabetes if you only take steroids for a short period of time. Talk to your doctor to find out what's best for you.
Cataracts
Cataracts can cause your vision to become cloudy or blurry. Steroid treatments can cause cataracts.
If you get cataracts, talk to your doctor about treatment options. In some cases, you may need to update your Crohn's treatment plan as a result.
Adrenal suppression
If you are taking an oral steroid treatment, be careful to follow your doctor's instructions. Do not skip a dose or stop the treatment on your own. A sudden disruption to your steroid treatment can lead to adrenal suppression, where the body doesn't have enough natural steroids built up.
Symptoms of adrenal suppression typically show up after a sudden stop to steroid treatment. They can include tiredness, weight loss, stomach pain, and more.
When you need to end a steroid treatment, your doctor will help you gradually reduce your dosage to give your body time to recover its natural steroids. If you notice a flare-up of Crohn's symptoms as you come off of a steroid, talk to your doctor about other medications to help you address those symptoms.
Muscle wasting
Your muscles may weaken after taking steroids, especially if you take steroids for several weeks or more. Older patients are at higher risk. If they're taken long-term, you may feel achy and notice muscle pain.
Ask your doctor about exercises to help keep you mobile and maintain muscle while you're on steroids. Aerobic exercise like walking, riding a bike, or going up the stairs is a good way to strengthen muscles.
Immunomodulator Side Effects
Hair thinning
The immunomodulator drug methotrexate (Rheumatrex) includes a side effect of hair loss. That's because methotrexate slows the growth of cells — both those that cause inflammation and those that help your hair grow.
Hair loss from methotrexate use is not usually severe. It is unlikely that entire patches of your hair will fall out. Once you stop taking the drug, your hair will probably grow back.
If your genes make you more likely to have male — or female — pattern baldness, drug-induced hair loss may speed up hair thinning or lead to permanent hair loss.
Your doctor may prescribe folic acid to help you maintain healthy hair while on methotrexate. But folic acid has not been proven to promote hair growth.
You can also consult a dermatologist about lotions and treatments to address hair loss.
Loss of appetite
A low appetite is a common symptom of Crohn's disease. The immunomodulators mercaptopurine (Purinethol) and tacrolimus (Prograf) both also include side effects of reduced appetite.
Talk to your doctor if you lose interest in eating. Your doctor can help you figure out whether your loss of appetite is due to Crohn's-related inflammation or a new drug you take.
You should also consult a dietitian to help you establish a diet that's right for you. You can also choose to eat smaller meals more regularly to maintain energy and prevent bloating. Focus on eating foods that are healthy and tasty.
Mouth sores
Several immunomodulators include a side effect of mouth sores. Azathioprine (Azasan, Imuran) and mercaptopurine (Purinethol) may be linked to canker sores. Methotrexate (Rheumatrex) is linked to more severe mouth sores.
There are many ways to treat mouth sores. Try a saltwater rinse. There are also a number of over-the-counter and prescription medications to help treat sores in your mouth.
If you notice extreme mouth sores, you might want to see a doctor about potential nutritional deficiencies impacting your oral health.
Avoid acidic, spicy, and salty foods that can make your sores worse.
Pancreatitis
Azathioprine and mercaptopurine include side effects of pancreatitis, or inflammation in the pancreas.
All patients taking immunomodulators should be monitored for possible irritation of the pancreas.
Common symptoms of pancreatitis include pain in your stomach and back. Other symptoms may include a quick heart rate, vomiting, and a fever. Consult your doctor right away if you notice unusual symptoms.
Bone marrow suppression
Immunomodulators can cause suppression of bone marrow in some people, which also means fewer blood cells are produced in your body as a result. It can heighten your risk of infection.
If you are on an immunomodulator drug for Crohn's disease, ask your doctor for regular blood tests to monitor for changes in your white blood cell count. That may be a sign of bone marrow suppression.
Side Effects of Biologics
Injection and infusion site reactions
Biologics given to you as a shot or through an IV pose a risk of allergic reactions.
A reaction at the injection site may include symptoms like itchiness, pain, reddened skin, and swelling.
If you receive your biologic as an infusion, a reaction could occur throughout your body. Common symptoms may include a fever, dizziness, and nausea.
Your doctor will monitor you while you receive an infusion or injection to help keep any side effects in check.
Joint pain
Biologics like certolizumab pegol (Cimzia) and natalizumab (Tysabri) include a side effect of joint pain.
If you notice new joint pain after taking a biologic, check with your doctor. They may consider other treatment options for you or examine other potential causes.
Respiratory infections
Since biologics suppress part of the immune system, they also make it easier for your body to develop infections. You may be particularly likely to get upper respiratory and lung infections.
To keep from getting sick, make sure you follow your doctor's guidance on vaccines. Get the latest versions when possible. Check with your doctor before getting any live virus vaccine to make sure it is safe with your Crohn's medications.
Increased risk of serious infections
In some cases, biologics can trigger flare-ups of serious infections like tuberculosis or hepatitis B.
Ask your doctor to test you for tuberculosis and hepatitis B before beginning a biologic treatment.
Increased risk of lymphoma
Researchers debate whether biologics can make it more likely to get lymphoma, a form of cancer. Since biologics are often taken in combination with other drugs that can lead to lymphoma, it is not yet clear whether biologics themselves play a role or not.
Talk to your doctor about the pros and cons of starting a biologic treatment for Crohn's disease. You'll need to weigh the risk of developing other forms of cancer linked to your untreated condition. People with Crohn's disease, for instance, get colorectal cancer at a higher rate.
JAK Inhibitor Side Effects
Acne
JAK inhibitors have been linked to a higher risk of acne. One recent study found patients using a JAK inhibitor drug were almost four times more likely to have acne.
If you notice significant acne after starting a JAK inhibitor treatment, talk to your doctor about options. You may be able to control the acne with topical acne treatments. If necessary, your doctor may consider reducing your drug dose.
Elevated Cholesterol or Liver Enzymes
You may notice higher cholesterol levels or more liver enzymes in your blood tests after starting a JAK inhibitor.
See your doctor regularly to check cholesterol and liver enzyme levels.
Blood Clots
Crohn's disease may increase your risk of blood clots. JAK inhibitors can also increase your risk of blood clots.
But side effects like blood clots have most often been reported in elderly patients taking JAK inhibitors for rheumatoid arthritis. Blood clots are not commonly seen in Crohn's patients using JAK inhibitors.
To prevent blood clots, focus on having a healthy lifestyle through exercise and diet. Stay hydrated. See your doctor to treat other health conditions you have that might put you at higher risk.
Shingles Reactivation
You are at a higher risk of contracting shingles, a reactivated version of the chickenpox virus, if you are on a JAK inhibitor.
If you are over age 50, consider getting the shingles vaccine as a preventive measure.
Takeaways
Crohn's disease is a form of irritable bowel disease that causes inflammation in your digestive tract. Symptoms include stomach pain, weight loss, and diarrhea.
There is no cure for Crohn's disease. Doctors use a variety of treatments to help address the condition. Currently prescribed drugs for Crohn's disease include aminosalicylates (5-ASAs), corticosteroids, immunomodulators, biologics, and JAK inhibitors.
Crohn's treatment options all have different side effects you should consider. Some common side effects shared across multiple drug types include headaches, nausea, and fatigue.
If you get new severe symptoms after starting a drug, don't hesitate to call your doctor.
"Any new concerning side effects, like bleeding, severe headache, those kinds of things," Moss says. "Call your team. Let them know this has happened, and let them then figure it out with you."
Make sure to talk to your doctor about the benefits and drawbacks of different treatments for Crohn's disease. Mention any other health conditions you have, and ask questions about common side effects.
Crohn's Disease Medication Side Effects FAQs
Which Crohn's medication has the least side effects?
Side effects vary widely from drug to drug and between types of Crohn's treatments. Talk to your doctor about which treatment options may be the best fit for your body and experience with Crohn's disease.
A medication with fewer listed side effects may still not be the best fit for you. Your doctor can help you consider a variety of things in choosing the treatments that will work best with your body.
Can medications cause Crohn's flare-ups?
Yes. Certain kinds of medications can lead to a higher risk of Crohn's flare-ups. Some common medications to avoid include certain types of NSAIDs (nonsteroidal anti-inflammatory drugs) like ibuprofen and naproxen sodium.
Talk to your doctor about which medications you should avoid with Crohn's disease.
What is the best medicine for Crohn's disease?
There is no single best medicine to treat Crohn's disease.
Work with your doctor to find the best treatment plan for you. This may include different medications and therapies. It could also include special diets and other lifestyle updates to manage your condition.
Plus, it's important to follow your doctor's instructions on how and when to take your medicine.
"The most common thing we notice with medications is not side effects. It's that people just don't take them as they're supposed to," Moss says. "People skip a few doses, or miss a dose here and there, and that unfortunately has negative consequences."
