What Are Crohn's Disease Symptoms?

Medically Reviewed by Poonam Sachdev on April 14, 2024
Written by Tammy Worth
13 min read

At some point, you've probably had stomach cramps with diarrhea or constipation. It’s uncomfortable, but it usually passes in a day or two. But if you have these symptoms often and they’re severe, there’s a chance you could have Crohn’s disease. 

Crohn's disease is a type of inflammatory bowel disease (IBD). With Crohn's, your immune system mistakes cells in your gastrointestinal (GI) tract as bad for you and attacks them. The symptoms of Crohn's disease can vary, depending on where the inflammation is in your GI tract. If you think you have Crohn's, talk to your doctor because symptoms can be similar to many other digestive conditions.   

Symptoms of Crohn’s vary widely depending on the person and the part of the  GI tract the disease attacks. It can impact different areas of the digestive system, but it often causes inflammation in the small intestine and bowels. Symptoms can be mild or so severe they lead to life-threatening complications. You may have signs of Crohn's disease off and on, and they may go away completely for periods of time, known as remission. 

Common Crohn’s disease symptoms

If your inflammation is in the lower GI tract, or colon, symptoms may be more frequent and stronger than if they are in the upper GI tract, or small intestine. These symptoms include: 

  • Belly pain and cramps
  • Blood in your stool
  • Diarrhea
  • Drainage from a painful sore near your anus
  • Urgent bowel movements
  • Feeling like you haven’t totally emptied your bowels
  • Loss of appetite and weight loss (talk to your doctor if you lose a lot of weight quickly) 
  • Constipation, which may lead to a blocked bowel

Silent Crohn’s disease symptoms

About one-fifth of people with the condition have no symptoms (silent Crohn’s) when the disease affects the small intestine. If your initial symptoms are silent, the next common signs of Crohn’s could include more serious ones like:

  • Intestinal blockage
  • Infection or abscess
  • Pain or fever that won’t go away
  • Hole or connecting tunnel in your intestine (fistula)
  • Cancer of the colon or small bowel
  • Increased risk of things like hospitalizations and bowel surgery

Other physical symptoms of Crohn's disease

The disease can also have symptoms that affect your overall health, including:

  • Fatigue
  • Fever (less common with Crohn’s, so consider calling your doctor)
  • Mouth sores
  • Night sweats
  • Unusual menstrual cycles
  • Anemia
  • Kidney stones

You might have one or many of these symptoms because Crohn's affects people in different ways. The symptoms can be mild, or they can leave you very weak. 

Crohn’s complications are less common than initial symptoms. They may be local, involving your intestinal tract, or systemic, affecting your entire body. 

Local complications of Crohn’s include:

Abscess. This pocket of pus results from a bacterial infection. It can form on your intestinal wall or near your anus. It can look like a boil and you'd notice swelling, tenderness, pain, and fever. The symptoms usually go away once the sore is drained. You may be given antibiotics to clear up the infection.

Fissure. Painful tears in the lining of the anus. They can cause bleeding during bowel movements. Topical creams and sitz baths are common treatments.

Fistula. Sores or ulcers can turn into openings that connect two parts of your intestine. They can also tunnel into nearby tissues like the bladder, vagina, and skin. Antibiotics can treat small fistulas. You may need surgery if yours are large or if there are many of them.

Malabsorption and malnutrition. The disease affects your small intestine, the part of your body that absorbs nutrients from food. Stomach pain keeps you from eating regularly, or your body may not be able to make the most of what you eat. This can sometimes cause low levels of nutrients like B12 and iron. Treatment focuses on replacing the missing nutrients.

Small intestinal bacterial overgrowth (SIBO). Your gut is full of bacteria that help you break down food. When this happens higher up in your digestive tract than usual, you can get gas, bloating, belly pain, and diarrhea. Antibiotics can help.

Strictures. These narrowed, thickened areas of your intestine result from the inflammation that comes with Crohn’s. They can be mild or severe, depending on how much of your intestine is blocked. Symptoms include cramping, belly pain, and bloating. Medication can help. But if it doesn’t work or if the blockage comes back often, you might need surgery.

With the exception of fissures, most of the above complications don’t happen often.

More than one-quarter of people with Crohn's have complications that aren't related to their gut. These are known as systemic, or extraintestinal, complications. They can impact various parts of the body. Some of the most common systemic complications are:

Joint inflammation

Crohn’s causes joint inflammation in about one-quarter of people who have the disease. Symptoms of joint inflammation -- or arthritis -- are pain, swelling, stiffness, and less flexibility. Crohn’s can lead to three main types of inflammation:

Peripheral. This type affects large joints in your arms and legs, like your elbows, knees, wrists, and ankles. The problems might start in one joint and then move to another (known as migratory). It’s most common if you have Crohn’s disease of the colon. The inflammation will come and go along with your Crohn’s, but it doesn’t usually cause lasting damage. 

Axial. This type affects your lower spine or lower back (sometimes called sacroiliac joints). It’s also known as spondylitis or spondyloarthropathy. You might even have symptoms of this before you’re diagnosed with Crohn’s. You could notice trouble breathing if it keeps your ribs from expanding. It can cause permanent damage if the bones in your spine fuse together.

Ankylosing spondylitis. This more serious type of spinal arthritis is rare among people with Crohn’s, but it can happen. In addition to causing arthritis in your back and very restricted movement, it can lead to inflammation in your eyes, lungs, and heart valves. Some people get it before a Crohn’s diagnosis. Doctors don’t know exactly what causes it, but they’ve found common genetic markers among people who have it. Ankylosing spondylitis is more common in people younger than age 30.

Treatment for arthritis with Crohn’s involves:

  • Easing the arthritis symptoms like pain, swelling, and inflammation with:
    • Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen. But people with Crohn’s can’t always take them because they irritate the lining of your intestines.
    • Steroids
    • Rest, heat, and range-of-motion exercises
  • Treating Crohn’s, usually with
    • Steroids
    • Sulfasalazine
    • Immune system drugs like methotrexate and biologics

Skin problems

Skin problems linked to Crohn’s are less common than joint inflammation. They are caused by the disease or by medications used to treat Crohn's. When they do occur, they most often include:

Erythema nodosum. These small, tender, red nodules usually show up on your shins, ankles, and sometimes your arms. They’ll get better as Crohn’s inflammation is controlled. Steroids can help reduce symptoms.

Pyoderma gangrenosum. These pus-filled sores often show up after an injury or other skin trauma. They usually appear on your legs but can show up anywhere. You might get them on your belly next to a stoma (hole in the stomach that lets waste come out to a colostomy bag) or surgery scars from a colectomy (surgery where part of the colon is removed). Over time, the sores join and form deep, long-lasting ulcers. Steroids, certain biologic drugs, and medications you put on your skin can help.

Skin tags. These small flaps of skin are common in people with Crohn’s, especially around the anus or hemorrhoids. Poop can attach to them and irritate your skin. Good skin hygiene can help manage them. Depending on the type of skin tag, your doctor may or may not recommend removing them through surgery. 

Mouth ulcers. You might hear them called canker sores. They are small, painful, round- or oval-shaped sores between your gum and lower lip or along the sides and bottom of your tongue. They get worse when the disease flares and ease when inflammation is under control. Symptoms can be relieved by using saltwater rinses, mouthwashes, topical steroids, and reducing intake of foods that are spicy, salty, and acidic.

Bone loss

This is a common complication of Crohn’s. In some cases, it could be due to the disease itself -- the proteins that cause inflammation change the pace at which old bone is removed and new is formed. It can also happen because of the powerful corticosteroid medications that doctors use to treat the disease. These drugs can:

  • Stop your body from absorbing calcium from food, which it needs to build bone
  • Make your body get rid of calcium when you pee
  • Boost production of cells that break down bone
  • Lower the number of cells that help form bone
  • Lower your body’s output of estrogen, which helps build bone

Bone density issues with Crohn's include having more porous bones (osteoporosis), less dense bones (osteopenia), or having soft bones (osteomalacia). 

Vitamin D deficiency

If your body can’t absorb vitamin D because of damage to the small bowel or a small bowel resection, you’re less likely to be able to absorb calcium and make bone.

To prevent problems or stop them from getting worse, you can:

  • Talk to your doctor about reducing the amount of steroids you take or trying one with fewer side effects
  • Take medications called bisphosphonates than can strengthen your bones, such as:
    • Alendronate (Fosamax)
    • Risedronate (Actonel)

Eye problems

Though it’s not very common, the inflammation in Crohn’s or the complications that come with it can affect your eyes. A condition called keratopathy, or unusual changes in the cornea, doesn't require treatment. Dry eyes can also happen and may need an antibiotic if there is an infection. Other, more serious, issues include:

Episcleritis. Inflammation of the area just beneath the conjunctiva (the clear tissue that covers the inside of your eyelids and the whites of your eyes) is the most common complication of Crohn’s. It can affect one eye or both. You’ll notice pain, itching, burning, and intense redness, but it won’t hurt your vision. Topical treatments can ease the symptoms. It will get better as your disease inflammation goes down.

Scleritis. This condition causes a constant pain that gets worse when you move your eyes. It can keep you awake. You may also have a headache; watery, red eyes; and light sensitivity. It can show up when you have symptoms of Crohn's or have none. If you have scleritis, your doctor will usually prescribe steroids or drugs that suppress your immune system. These will help reduce symptoms and keep scleritis from coming back. If you have scleritis repeatedly, over time it can cause your sclera (the white part of your eye) to become thin and tear.

Uveitis. This is a painful inflammation of the uvea, the middle layer of your eye. It can cause pain, blurry vision, light sensitivity, and redness. Your doctor may prescribe eye drops with steroids to ease the inflammation. When you have Crohn's under control, uveitis symptoms usually improve. But if you don’t get uveitis treated, it could lead to glaucoma (damage to the optic nerve that causes eye pressure) and blindness.

Kidney problems

Also possible, but uncommon, is that Crohn’s starts to affect your kidneys. The issues are usually mild and are often caused by medications used to treat Crohn's disease. Problems with your kidneys could include: 

Kidney stones. There are two kinds: calcium oxalate and uric acid stones. Oxalate stones are a common problem with Crohn’s because your body has a hard time absorbing fat. Instead, the fat binds to calcium and leaves a salt called oxalate that gets absorbed into your kidneys and can turn into stones. The risk goes up if you have a small bowel resection, which makes you more likely to get dehydrated. Symptoms of kidney stones include pain, blood in the urine, nausea, and vomiting. Treatment involves drinking more water and following a diet with lots of juices and vegetables. if the stones don't pass on their own, your doctor may have to take them out surgically. Uric acid stones form when diarrhea makes your urine more acidic. 

Hydronephrosis. This happens when the ileum (where your small intestine meets the large) swells from Crohn’s and puts pressure on your ureter, the tube that carries urine from your kidney to your bladder. When urine can’t drain like it should, your kidney swells, and scar tissue can form. You might notice a dull pain near your kidney and blood in your urine. Surgery to remove inflamed tissue and the part of the bowel that’s causing the problem can resolve it.

Fistulas. In addition to forming within your intestines, fistulas can develop between the intestine and other organs, like the bladder or ureter. It’s more likely to affect men and can lead to urinary tract infections. Medications can help, but you might need surgery.

Amyloidosis (too much protein in the kidneys) and glomerulonephritis (a lesion that reduces the kidneys' ability to filter) are other potential, but rare, kidney complications.   

Liver problems

Issues with your liver are rare but can happen in some people with Crohn’s. Your liver processes everything you eat and drink. Crohn’s disease, or treatments for Crohn's, can cause inflammation or damage. You’re only likely to notice low energy and fatigue unless you develop a more serious problem. Among the most common issues:

Fatty liver disease. When your body doesn’t process fats as well, they can build up in your liver. Getting your weight to a healthy level and cholesterol under control (below 200 for total cholesterol) will reduce the amount of fat in your liver.

Gallstones. They form when little pieces of cholesterol or bilirubin (made during the breakdown of red blood cells) turn into stones inside your gallbladder and block the bile ducts. Medication and surgery are treatment options.

Hepatitis. Long-term liver inflammation can result from Crohn’s disease or medications, like methotrexate, used to treat Crohn's. Hepatitis is treated with medications to reduce inflammation.

Pancreatitis. Inflammation of the pancreas can result from gallstones and medications. It can cause pain, nausea, vomiting, and fever. Stopping the medication or removing the gallstone can fix the problem.

Primary sclerosing cholangitis. This is a disease of the bile ducts, tubes that carry bile from your liver to your small intestine. It causes scarring in the ducts that makes them narrow. It can lead to liver damage and failure. Dilation and stents can help open blocked ducts. Your doctor might prescribe antibiotics or other meds called bile acid sequestrants. 

Physical development problems

This is a fairly common problem with Crohn’s, especially in kids. The disease can start at any age. When kids get Crohn’s, parents are likely to notice:

  • Growth failure. Kids with Crohn’s are likely to be shorter and weigh less than those without. They may stop getting taller before symptoms start.
  • Delayed puberty.Kids with Crohn’s are likely to start puberty later than their friends.

Lots of factors can cause Crohn’s diarrhea, and many are linked. One problem leads to another and then another. The main trigger is inflammation. Here’s how it can harm your gut:

Fluid and electrolyte imbalances. As much as 42 cups of fluid enter your intestine every day. Normally, fluids flow freely back and forth through the gut wall, along with nutrients and electrolytes – important minerals like sodium and chloride. Electrolytes help move fluid in and out of your cells. When inflammation affects their function, too much water stays in your gut, and the result is diarrhea.

Damage to the gut lining. Inflammation can damage epithelial cells in the gut lining. This thin layer of tightly packed cells acts as a barrier to keep out toxins and germs while it lets in fluids and electrolytes. When it’s damaged, the proteins that glue the cells together can leak. This allows proteins and bacteria to escape into your body where they cause even more inflammation and worse diarrhea.

Altered microbiome (dysbiosis). The microbiome is the common name for the trillions of mostly friendly bacteria, viruses, and fungi that live on and in your body. Though they’re in every nook and cranny – including between your toes – most are in your gut. These microbes perform functions that are essential for life and health. They help digest your food, make vitamins, and boost your immune system. When antibiotics, a poor diet, smoking, or stress upset the delicate balance of the microbiome, lots can go wrong. Unfriendly bacteria can overwhelm friendly ones. You may also have fewer different types of bacteria (bacterial diversity). This is important because lower diversity is linked to diarrhea that doesn’t go away after your gut has healed. Also, because the microbiome can’t control your immune system the way it normally would, you may have lots more inflammation – and more diarrhea.

Bile acids. Bile is a substance made in your liver that helps digest fats. Your body usually releases the right amount of bile based on the food you eat. If your body produces too much bile or can’t use it correctly, you may develop what’s known as bile acid diarrhea (BAD). It can trigger an urgent need to poop. You might have trouble controlling your urine, too. BAD is common in people with Crohn’s who have had parts of the small bowel removed.

Crohn’s disease is often confused with another condition called ulcerative colitis. The symptoms are similar, and both are kinds of IBD. They involve periods of active flare-ups of inflammation followed by times when you don’t have symptoms, which is called remission.

Differences between the two conditions are:

  • Ulcerative colitis affects your colon while Crohn's can happen from your mouth to anus.
  • Ulcerative colitis inflames the inner colon lining while Crohn's can inflame all layers of the bowel walls.
  • Ulcerative colitis causes inflammation in the whole colon, but you can have both healthy and inflamed parts of the intestine with Crohn's.

The only way to find out if you have Crohn’s or ulcerative colitis is to see your doctor for tests. A small number of people with IBD can have both conditions at once.

Crohn's disease is an inflammatory bowel condition that can cause severe symptoms related to your gut as well as the rest of your body. If you think you may have Corhn's, talk to your doctor. The condition is lifelong and can't be cured, but the earlier you begin treatment, the better chance you have of relieving symptoms and reducing damage to your gut.

Can you suddenly develop Crohn's disease? Symptoms usually appear over time, but they can come on suddenly. They can also come and go (known as flare-ups and remission). 

What does Crohn's flare-up feel like? Symptoms of a flare-up include stomach pain, chronic diarrhea, blood in your stool, fatigue, canker sores, and sores around your anus. 

Which foods trigger Crohn's disease? Trigger foods may be different for each person with Crohn's and you may not have any. Foods that may worsen symptoms include:

  • High-fiber foods
  • Foods with lactose, like milk and yogurt
  • Artificial sweeteners
  • Sugary foods and drinks
  • High-fat foods
  • Spicy foods
  • Alcohol and caffeine