Ulcerative colitis and Crohn's disease are both Inflammatory Bowel Diseases (IBD). There are many differences. The main one is which intestine is inflamed. Ulcerative colitis just hurts the colon. Where Crohn’s can hurt any part of the intestine tract. Crohn’s can inflame just the small intestine or just the colon or both. Another difference is which layer of the intestine is inflamed. Ulcerative colitis just hurts the inside layer. Crohn’s disease can also hurt the inside layer. But it can also hurt all of the layers. This is also called the wall of the intestine.
IBD is from inflammation in the bowels. This can cause bleeding, pain, diarrhea and fever. This inflammation can be seen on tests. These include x-rays like a CT scan or a colonoscopy. Irritable bowel syndrome (IBS) can be from a sensitive intestine. Or it is because the intestine is moving too slow or too fast. It is not because of inflammation. There can be diarrhea and abdominal pain with IBS. There can also be constipation and bloating. But there should be no bleeding or fever. It cannot be seen on any tests like IBD can.
There is not a single cause for IBD. It is a combination of things. Certain genes from your family can make it happen. Around 10 percent of people with IBD have a close relative with it as well. The other major reason is because of how your immune system developed. Being fed breast milk or formula can change the immune system. Taking antibiotics as a child or living on a farm or in the city can change things too. Then one day an infection or allergic reaction happens in the intestine turning the immune system on. But in IBD the immune system never turns back off. This results in ongoing inflammation causing the symptoms.
Emotional stress does not cause IBD. It also does not cause IBS either. But stress can cause abdominal pain and diarrhea to occur. This could be from making the inflammation in IBD worse. Or it can be from making Irritable Bowel Syndrome worse. Studies show flares of IBD can happen more often during stressful times. They also show stress can make IBS symptoms worse as well. This is because the brain and the gut are linked. So keeping stress levels low can help keep IBD under control.
There is no one test that can tell if you do or don’t have IBD. IBD is diagnosed from the story you give, how you look and a combination of tests. Colonoscopy is one of the best tests to see if IBD is there or not. This allows biopsies to be taken of the intestine lining. Looking at the lining under a microscope can see inflammation. Another good test is an x-ray such as a CT scan. This can see areas the colonoscopy cannot reach. Other tests can look at your blood or stool for inflammation. And one blood test looks at a lot of different things to see if IBD could be there. Taking all of these results together makes the diagnosis.
Ulcerative colitis and Crohn's disease can lead to diarrhea, bleeding, anemia, weight loss, fevers, malnutrition and fistulae. Crohn’s disease can cause scarring of intestines leading to blockage. They also increase risk of intestinal and other types of cancers. IBD can also have extra-intestinal manifestations where areas other than your gastrointestinal system such as your skeletal system, your skin or your eyes may be involved.
Physicians prefer to maintain good nutrition for those diagnosed with IBD. If you are responding well to medical management, you can often eat a reasonably unrestricted diet. We encourage well balanced diet with a variety of nutrients. Recent data have shown us that a diet rich in whole grains, fresh fruits and vegetables, low in red meat and more in white meat / Fish is helpful in these conditions to reduce inflammation. In certain subsets of patients with scarring ( fibrosis / stenosis of intestines, A low-roughage diet is recommended. If you appear to be milk sensitive (lactose intolerant), you are advised to either avoid milk products or use milk to which the enzyme lactase has been added. Since other autoimmune diseases can occur together, a Gluten intolerance may be present and gluten free diet can reduce symptoms but this needs to be confirmed by testing.
With early and proper treatment, most patients with IBD lead healthy and productive lives. Studies have shown reduction in need for hospitalization and surgery in significant number of patients with medical therapy. About 50% to 70% of patients with Crohn’s disease and 15-30% of patients with Ulcerative colitis end up requiring surgery within 10-20 years after diagnosis. These surgical trends have shown improvement with medical therapy.
Crohn's disease of the small or large intestine can be treated surgically for complications such as obstruction, abscess, fistula or failure to respond adequately to treatment. The disease may recur at some time after the operation.
Ulcerative colitis is curable with removal of the entire colon. This may require creating an "ileostomy" (with attachment of the ileum to the external abdominal wall with an external application pouch) or may involve the direct attachment of the small intestine (ileum) to the anus. This type of surgery, known as "IPAA surgery," does not require an external application pouch.
If you have persistent symptoms such as diarrhea and abdominal pain or cramps, it could be Crohn’s disease. A chronic disorder, Crohn’s disease may cause you to have a wide-range of digestive symptoms that may be mild or severe and may flare up over time.
Crohn’s disease is when there is irritation in the intestines. This is a type of inflammatory bowel disease (IBD). It can affect anywhere from the mouth to the anus (end of the bowel).
Crohn’s disease usually occurs in the last part of the small intestine and the beginning of the colon. Sometimes it can show up in patches anywhere in the intestines though. If the irritation goes on for too long it can cause damage. This damage can be scar which narrows the bowel. Also, the body can form a tunnel going from inside the bowel out to the surface. This is called a fistula and can attach the bowels to other body parts like the skin or bladder. When this happens other problems can occur.
Since Crohn’s disease has no cure, medicines are need to keep it under control. Usually this works and people can go a long time without issues. But sometimes Crohn’s can still flare up even when on medicine. If that happens, different medicines can be tried. It is important to always take your medicine even when you feel good. If the irritation in gut comes back, you may not feel it. If irritation goes on for a long time, damage can happen that may need surgery to fix. The best way stop that is to look for signs of irritation and damage. Seeing your doctor for check-ups can do this and help you feel as good as possible.
Women who have Crohn’s disease can get pregnant and everything be normal. If you have Crohn’s disease and want to get pregnant, you should talk with your Crohn’s doctor first. The best time to get pregnant is when you are feeling good. This will lower the chances of any problems with the pregnancy. If you do get pregnant when the irritation is bad, that can higher the chances of problems like losing the baby. This is why it’s important to keep the irritation under control after you get pregnant.
Signs and symptoms can be mild or severe and can be different. It depends on the part of the digestive tract involved. Symptoms usually build over time but also can happen suddenly.
The most common symptoms of Crohn’s disease are:
Other symptoms may include:
The signs and symptoms of Crohn’s disease can be like other conditions. If you have any symptoms, or changes in your bowel habits that don’t go away, see your doctor and get checked out.
Doctors don’t know the exact causes of Crohn’s disease. They think certain factors could be involved, such as:
Risk factors for Crohn’s disease can include:
See your doctor if you have any of the signs, symptoms, or risk factors for Crohn’s disease. Your doctor will perform an exam and testing. This will see if you do have it or another condition instead.
Your doctor will hear your symptoms, medical history and risk factors. They will also do an exam looking for any signs. No one test for Crohn’s disease exists, but a mixture of tests can rule out other problems and make the diagnosis.
Tests that you may need:
Doctors may also use diagnostic procedures such as:
Currently, there is no cure for Crohn’s disease. But treatments work differently in different people. There are many goals of treatment. They are to relieve symptoms and improve your quality of life. Also to heal the inflammation and prevent damage.
Doctors usually start medicines to make symptoms go away. Then you can get medicines to keep it under control and prevent it from coming back.
Your doctor may use one or more medications such as:
If other treatments do not work or if a complication happens, then surgery can be done. This is just a short-term fix though. Surgery will not cure the Crohn’s disease. The surgeon just removes the damaged or abnormal part of the digestive tract and reconnects the healthy areas. About half of the people with Crohn’s disease need surgery over the course of their lifetime.
Complementary and alternative medicine (CAM) therapies, such as acupuncture, fish oil, or nutritional supplements, have not shown much benefit for treating Crohn’s disease.
People with Crohn’s disease can develop problems due to the condition. Others may have side effects from medications. Some common issues include:
If you have Crohn’s disease, healthy lifestyle habits can help you maintain a good quality of life. Talk to your doctor about:
Ulcerative colitis (UC) is when the lining of the large intestine gets inflamed. The large intestine is made up of the colon and the rectum. When this gets inflamed, symptoms of UC start.
UC involves the rectum in everyone. But in some people, it can affect the whole colon. UC belongs to a group of diseases called inflammatory bowel diseases. The other main one being Crohn's disease (CD). Though it was once thought that UC and CD were different, as many as 10% of patients can have features of both. This is called IBD-U (IBD-Unclassified).
These depend on how bad the inflammation is and the amount of the colon that is involved.
In mild to moderate inflammation, symptoms can include:
If severe inflammation is present, patients can also get:
Some of the symptoms of UC may be non-specific and could be caused by other diseases such as Crohn's disease, irritable bowel syndrome, or infection. Your doctor can help determine the cause of your symptoms and should be consulted should you experience a significant change in your symptoms.
Your doctor may suspect UC based on your symptoms. However, tests will need to be done to make the diagnosis.
All patients with symptoms of UC should have a colonoscopy or flexible sigmoidoscopy. This will confirm the diagnosis. During this procedure, your doctor will see the lining of your colon and rectum. This can see signs of irritation and small tissue samples (biopsies) can be taken. The samples are looked at under a microscope to see if it is UC.
Why patients get UC is still poorly understood.
Causes may include a variety of factors:
The complications of UC can be split into those that affect the colon or other parts of the body.
Within the colon, UC can rarely lead to colon cancer or toxic megacolon (a rare but potentially deadly widening of the large intestine).
UC is known to increase the risk of colon cancer. Patients with UC symptoms for 8 or more years and those with more of the colon affected are at higher risk. Overall, the risk of colon cancer increases 0.5 percent every year after ten years of disease. Therefore, a colonoscopy is needed every one or two years starting 8 years after symptoms begin.
Patients with inflammation of the bile ducts, called primary sclerosing cholangitis (PSC), are at highest risk for colon cancer and need a colonoscopy every year as soon as PSC is found.
Luckily colon cancer is rare in UC. It may not happen if the inflammation of the colon is kept under control. By doing careful colonoscopy exams, biopsies can look for pre-cancerous changes called dysplasia under the microscope. If these are seen, further things can be done to remove it and prevent cancer from forming.
Patients with UC are also at risk for extra-intestinal manifestations of UC (complications outside of the colon). These complications often involve the liver, skin, eyes, mouth, and joints.
In the liver, patients may get primary sclerosing cholangitis. This occurs in about 3% of patients with UC. PSC can progress even if UC is not active. It is often detected by increases in liver blood tests. A special MRI scan such as a Magnetic Resonance Cholangiopancreatography (MRCP) can see it. Other times a procedure called an Endoscopic Retrograde Cholangiopancreatography (ERCP) is done.
Patients with UC can develop sores in the mouth or rashes on the skin. These usually appear when UC symptoms are active. The most common rashes that are seen in UC are erythema nodosum (EN) and pyoderma gangrenosum (PG).
Arthritis is commonly associated with UC. It can involve small joints (such as the fingers/toes) or large joints (often the knee). When smaller joints are hurting, they may be going on at the same time as a UC flare. The joints of the spine can be affected as well, but this is less common than it is in Crohn's disease.
Anxiety and depression can be common. This is the same in any chronic condition. UC can be irregular and the need to take daily medicines can be frustrating. Even though these feelings are normal, bad anxiety or depression should be discussed with your doctor. There are many support groups for trouble coping with UC (see the final section).
UC can present in different ways. UC is often a chronic, life-long condition. It is often diagnosed between the ages of 11 and 30. Although it can be diagnosed at any age. Early symptoms can be mild and may be confused with other conditions such as Irritable Bowel Syndrome. Other times they are very severe and require a hospital stay and surgery. Usually, symptoms vary over time. There can be times where symptoms are constant. Other times symptoms are fully gone. Rarely though will someone just have a single flare.
People with a severe first attack or those whose entire colon is affected usually have a more aggressive course. This means more frequent flares and shorter periods of being symptom-free. The good news is that patients are still able to function well. Also, life expectancy is the same as those without UC.
Medical treatment of UC has two separate goals:
Surgery is also a treatment option for UC and will be discussed separately. Medication choices can be grouped into four general categories:
Aminosalicylates are a group of anti-inflammatory medications. Examples include sulfasalazine, mesalamine, olsalazine, and balsalazide. These are used to get rid of inflammation and keep it gone. They are used in mild to moderate UC. They come in both pill and rectal forms (suppositories and enemas). They work on the lining of the colon to decrease inflammation. They are generally well tolerated. The most common side effects include nausea and rash. Rectal forms of mesalamine are used more often if UC is just the end of their colon.
Steroids (prednisone or budesonide) work well to get rid of inflammation. They come in oral, rectal, and intravenous (IV) forms. They can be used in more moderate to severe cases. Some steroids are absorbed into the blood and have a number of side effects. That’s why they are not a good option for long-term use. Side effects include cataracts, osteoporosis (thinning of the bones), mood effects, and increased chance of infections. Others are high blood pressure, high blood sugar and weight gain. Some steroids are less absorbed and work mainly in the colon with less side effects.
Immunomodulators include medications such as 6-mercaptopurine and azathioprine (thiopurines). These are taken in pill form and absorbed into the bloodstream. They work to just keep inflammation gone but are slow to work. They can take up to two to three months to really help. Because of this, these are usually combined with other medications (such as steroids). Typically, in those with moderate to severe disease. Frequent blood tests are needed though. That is because these can injure the liver or decrease blood cells. If either happen, they go away after stopping the drug. Other side effects include nausea, rash, inflammation of the pancreas, and, rarely, lymphoma.
Biologic agents are medications given by IV or a shot, that are used to treat moderate to severe UC. There are several different types.
Tofacitinib is a newer oral drug (not a biological therapy). It too can induce and maintain remission of UC. Tofacitinib (Xeljanz®) works by blocking an enzyme that is needed to turn on inflammation. This drug can work quickly. However, it may increase cholesterol levels. It also may increase the risk of getting the shingles infection (related to chicken pox). This risk can be decreased by getting the shingles vaccine.
The most recent oral drug that’s not a biologic is called ozanimod. Ozanimod (Zeposia ®) works to block the blood cells that cause inflammation from ever leaving the lymph nodes. This has been shown to help in both moderate and severe UC but can decrease the heart rate or cause swelling of the eye. An electrocardiogram (ECG) should be done before starting. Also, if you have a history of conditions affecting the eye, such as uveitis, you may not be able to use this drug.
As with all medications, you should discuss the risks and benefits with your doctor.
Other medications used less frequently for UC include cyclosporine and tacrolimus. These drugs are sometimes used in those rare cases of severe UC that don’t respond to anything else. Side effects can include infections and kidney problems. These are only offered at a limited number of hospitals and are usually used for a short period of time. If used, the goal is to get you better long enough to get onto other drugs for long-term.
Taking Medication for UC as Prescribed: No matter which medication you and your doctor decide on, it is very important to take it as directed. No medical therapy can work if it is not taken. Missing doses can lead to treatments that may have been avoided if not mentioned to your doctor. Plus, uncontrolled inflammation is what causes many of the complications. By taking your medicine, the chances of these happening are decreased.
Surgery in UC is performed for a number of reasons. It is generally considered to cure UC if the entire large intestine is removed. Some common reasons to need the colon removed are:
Several different surgeries are performed for UC. The choice of surgery depends on what the patient wants and the experience of the surgeon. The most common surgery is total proctocolectomy with ileal pouch anal anastomosis. This is when the whole colon and rectum are removed. Then the small intestine is used to make a new area to hold stool. This new area is called a “J pouch.” This operation usually requires two separate surgeries to complete although it may require three stages in really sick patients.
Following this surgery, patients can expect five to ten stools a day. This is because they no longer have a colon to store stool. Patients usually feel better because their symptoms are gone, and their medications can be stopped. However, inflammation of the pouch known as pouchitis can still happen afterwards which is usually treated with antibiotics. Women who have this surgery may have a decreased ability to get pregnant naturally.
Another common surgical procedure involves a proctocolectomy with ileostomy (removal of the entire colon and rectum and connection of the small intestine to the abdominal wall so that stool empties into a bag). This procedure is often done in elderly patients, obese patients, or those with anal dysfunction. Should you need a surgical procedure for UC, your surgeon can help you decide which type of surgery best fits your needs.
Many alternative therapies have also been studied to treat UC. No studies have suggested that diet can either cause or treat UC. All that is advised is that people eat a well-balanced diet. Likewise, there is no convincing evidence that UC results from food allergies. Though vitamin and mineral deficiencies are more common in Crohn's disease, some vitamin deficiencies can also happen in UC patients. For this reason, a multivitamin and a calcium supplement may be needed.
Probiotics are species of bacteria that are proposed to help the bowel. There have been a number of scientific studies conducted to see how probiotics could help UC. Most of these have not been shown to help UC, so probiotics are usually not recommended.
Other herbal remedies and alternative therapies have been studied for use in patients with IBD such as curcumin (comes from the herb turmeric) and parasitic worms (helminths). Though studies have shown promise for several alternative therapies, these have not yet been shown to be safe and effective. Therefore, they are currently not used.
UC is a chronic disease so having a GI doctor with experience in seeing people with UC is best. Many of the medicines used need regular bloodwork. This is to make sure they are not causing any serious problems. Patients with UC have a higher risk of osteoporosis (thinning of the bones). This can be from the disease itself or from long term or frequent steroid use. Therefore, your doctor may recommend checking Vitamin D levels and a bone mineral density test called a DEXA scan. Colorectal cancer screening is also important because of the higher risk of cancer in patients with UC as discussed earlier.
Many organizations provide support and information for patients with UC. The ACG website has additional information. The Crohn's and Colitis Foundation has extensive patient information. They also have links to various other social, financial, and medical support groups. Other sources of information include the individual drug company websites, and, most importantly, your doctor.
IBD Overview:
Justin A. Crocker, MD, FACG, Duke GI of Raleigh, Raleigh, NC, and Rohit Singhania, MD, FACG, Connecticut GI, Manchester, CT – Published July 2024.
Crohn's Disease:
Bhavik M. Bhandari, MD, Robert Wood Johnson Medical School, New Brunswick NJ, and Joyann Kroser, MD, FACG, Crozer Gastroenterology Associates, Upland, PA – Published March 2011.
Gary R. Lichtenstein, MD, FACG, University of Pennsylvania, Philadelphia, PA, and David T. Rubin, MD, FACG, University of Chicago, Chicago, IL – Reviewed/Revised June 2019.
Joseph Feuerstein, MD, Beth Israel Deaconess, Boston, MA – Updated April 2021.
Justin A. Crocker, MD, FACG, Duke GI of Raleigh, Raleigh, NC – Updated April 2024.
Ulcerative Colitis:
Richard S. Bloomfeld, MD, FACG, and Sean P. Lynch, MD, Wake Forest University School of Medicine – Published May 2010.
Richard S. Bloomfeld, MD, FACG, Wake Forest University School of Medicine – Updated February 2016.
David T. Rubin, MD, FACG, University of Chicago – Updated June 2019.
Justin A. Crocker, MD, FACG, Duke GI of Raleigh, Raleigh, NC – Updated April 2024.