Inflammatory Bowel Disease (IBD)

Introduction

Inflammatory bowel disease, usually shortened to IBD, is a long-term condition in which the digestive tract becomes inflamed. The two main forms are Crohn’s disease and ulcerative colitis. Both cause symptoms such as diarrhoea, abdominal pain, fatigue, weight loss, and sometimes bleeding. Both tend to follow a pattern of flares (when symptoms get worse) and remission (when symptoms settle).

If you have been diagnosed with IBD, you are not alone, and you are not facing a condition without options. Modern treatment has changed substantially over the past two decades. Many people with IBD now reach long, stable periods of remission with the right combination of medication, monitoring, lifestyle adjustments, and — when needed — surgery.

This article is written for people who already have an IBD diagnosis, or who are being investigated and want to understand what lies ahead. It explains the two main types of IBD, what causes them, how they are diagnosed, the treatment options doctors typically consider, what daily life with IBD can look like, and how children with IBD are cared for. The aim is to give you a clear picture of the condition so you can have informed conversations with your gastroenterologist.

What Is Inflammatory Bowel Disease?

Inflammatory bowel disease is a group of chronic conditions in which the body’s immune system causes ongoing inflammation in the lining of the digestive tract. The inflammation is not caused by an infection that can be cured with antibiotics. Instead, the immune system reacts in a way that damages the gut over time.

IBD is different from irritable bowel syndrome (IBS), even though the names sound similar. IBS is a disorder of how the bowel functions and causes symptoms, but it does not damage the bowel wall or cause visible inflammation. IBD does both.

IBD is also different from short-term gut inflammation caused by food poisoning or stomach infections. Those usually settle within days or weeks. IBD is lifelong, although its activity rises and falls over time.

The condition can affect people of any age but is most often diagnosed between the ages of 15 and 35. A second, smaller peak of new diagnoses happens between 50 and 70. IBD can run in families, but most people with IBD do not have a close relative who also has it.

Types of IBD

Crohn’s Disease

Crohn’s disease can affect any part of the digestive tract, from the mouth to the anus. Most often it involves the last part of the small intestine (the ileum) and the beginning of the large intestine (the colon). The inflammation can occur in patches, with healthy bowel in between — doctors call these “skip lesions.”

In Crohn’s, inflammation goes deep through the full thickness of the bowel wall. Over time this can lead to:

• Strictures — narrowed segments of bowel that can block the passage of food
• Fistulas — abnormal tunnels that form between the bowel and other organs, the skin, or another loop of bowel
• Abscesses — pockets of infection
• Perianal disease — inflammation, tears, or fistulas around the anus

Common symptoms of Crohn’s include abdominal pain (often in the lower right side), diarrhoea, weight loss, tiredness, and sometimes fever.

Ulcerative Colitis

Ulcerative colitis affects only the colon (large intestine) and the rectum. The inflammation is continuous, starting from the rectum and extending upward for a variable distance. Unlike Crohn’s, the inflammation is limited to the inner lining of the bowel wall.

Doctors often describe ulcerative colitis by how much of the colon is involved:

• Proctitis — only the rectum
• Left-sided colitis — the rectum and the left side of the colon
• Extensive colitis or pancolitis — most or all of the colon

Typical symptoms include bloody diarrhoea, an urgent need to pass stool, cramping pain in the lower abdomen, and sometimes passing mucus. People with severe disease may also have fever, weight loss, and significant fatigue.

Indeterminate Colitis

In some people, inflammation is limited to the colon but does not clearly match either Crohn’s or ulcerative colitis. Doctors call this indeterminate colitis. Over time, with further investigation, it often becomes clearer which type the person has.

Causes and Risk Factors

The exact cause of IBD is not fully understood. Current thinking is that IBD develops when several factors come together in the same person:

Genetics. More than 200 genes have been linked to IBD risk. Having a parent or sibling with IBD raises your own risk, although most people with IBD do not have a strong family history.

The immune system. In IBD, the immune system reacts against the normal contents of the gut — including the bacteria that live there — and triggers inflammation that does not switch off properly.

The gut microbiome. The mix of bacteria living in the gut is different in people with IBD compared with healthy people. Whether this is a cause or a consequence is still being studied.

Environmental factors. Several environmental factors are linked with IBD risk, including:

• Smoking — raises the risk of Crohn’s disease and makes it more severe; interestingly, it has the opposite effect in ulcerative colitis, though this is not a reason to start or continue smoking, given the many other harms
• A history of certain gut infections
• Frequent use of antibiotics in childhood
• Living in industrialised, urban settings
• Diets high in ultra-processed foods (a likely but still-debated link)

It is important to know that IBD is not caused by stress, by anything you ate or did not eat, by poor parenting, or by any personal failing. Stress and diet can influence symptoms, but they do not cause the underlying disease.

Signs, Symptoms, and Flares

If you already have an IBD diagnosis, you will be familiar with your typical symptoms. This section focuses on recognising flares and changes that warrant contacting your doctor.

Common signs of a flare include:

• Diarrhoea returning or becoming more frequent
• Blood or mucus in the stool
• New or worsening abdominal pain or cramping
• Urgent need to pass stool, including at night
• Unexplained weight loss
• Persistent tiredness or feeling unwell
• Low-grade fever
• Reduced appetite

IBD can also cause symptoms outside the gut. These are called extraintestinal manifestations and include:

• Joint pain or arthritis
• Skin rashes such as erythema nodosum or pyoderma gangrenosum
• Eye inflammation (uveitis, episcleritis)
• Mouth ulcers
• Liver inflammation, in particular a condition called primary sclerosing cholangitis

Some symptoms need urgent medical attention. Contact your doctor or seek emergency care if you have heavy rectal bleeding, severe abdominal pain, persistent vomiting, signs of dehydration, a high fever, or a swollen and tender abdomen. These can be signs of complications such as a bowel obstruction, severe flare, or in rare cases toxic megacolon, where the colon dilates dangerously.

Diagnosis

There is no single test that diagnoses IBD. Doctors put together information from several sources to confirm the diagnosis, identify the type, and judge how active and how widespread the disease is.

Clinical Assessment

The first step is a detailed conversation about your symptoms, how long they have been present, your family history, and any other health problems. Your doctor will also examine your abdomen and check for signs such as weight loss, anaemia, or perianal disease.

Blood and Stool Tests

Blood tests can show:

• Anaemia (low red blood cell count), often from blood loss or chronic inflammation
• Raised inflammation markers, such as C-reactive protein (CRP)
• Low levels of iron, vitamin B12, vitamin D, or other nutrients

Stool tests can:

• Rule out infections such as Clostridioides difficile or parasitic infections that can mimic or worsen IBD
• Measure faecal calprotectin, a protein released into stool when the bowel is inflamed; this is a useful marker for distinguishing IBD from non-inflammatory conditions like IBS and for tracking disease activity over time

Endoscopy

A colonoscopy is usually the most important test. A thin, flexible tube with a camera is passed through the anus into the colon and, where possible, into the last part of the small intestine. Your doctor can see the inflammation directly and take small tissue samples (biopsies) to examine under a microscope. Biopsies are essential for confirming the diagnosis and telling Crohn’s and ulcerative colitis apart.

If the small intestine higher up is suspected of being involved — especially in Crohn’s — an upper endoscopy or a capsule endoscopy (a tiny camera in a swallowable capsule) may be used.

Imaging

Cross-sectional imaging helps assess areas of the bowel that endoscopy cannot easily reach, and detects complications like fistulas, abscesses, or strictures. Common tests include:

• MRI enterography — a detailed scan of the small bowel, often preferred because it avoids radiation
• CT enterography — useful in urgent situations
• Pelvic MRI — particularly important when there is perianal Crohn’s disease with fistulas
• Abdominal ultrasound — used in some centres to monitor bowel inflammation without radiation

Once the diagnosis is confirmed, your doctor will describe the location and extent of disease, judge its severity, and discuss a treatment plan.

Treatment and Management

The goals of IBD treatment, as set out by major bodies such as the American College of Gastroenterology (ACG), the American Gastroenterological Association (AGA), and the European Crohn’s and Colitis Organisation (ECCO), are to:

• Bring an active flare under control (induce remission)
• Keep the disease quiet over time (maintain remission)
• Heal the lining of the bowel where possible
• Prevent complications
• Maintain quality of life, growth (in children), and ability to work and study

Treatment is chosen based on the type of IBD, where it is in the bowel, how severe it is, your age and other health conditions, and your response to previous medications. Modern guidelines increasingly favour a “treat-to-target” approach — aiming for specific objective signs of improvement (such as a falling faecal calprotectin or healing seen on endoscopy), not just symptom relief.

Aminosalicylates (5-ASAs)

Medications such as mesalamine (also called mesalazine) and sulfasalazine reduce inflammation in the lining of the colon. They are commonly used in mild to moderate ulcerative colitis, both to bring flares under control and to maintain remission. They have a limited role in Crohn’s disease. They are available as tablets, granules, enemas, and suppositories.

Corticosteroids

Steroids such as prednisolone or budesonide are powerful anti-inflammatory medicines used to bring flares under control quickly. They are not suitable for long-term use because of side effects such as weight gain, mood changes, raised blood sugar, bone thinning, and increased infection risk. Doctors typically aim to taper steroids off once the flare is controlled and to maintain remission with other medications.

Immunomodulators

Medications such as azathioprine, mercaptopurine, and methotrexate dampen the immune system to keep inflammation under control over the long term. They take several weeks or months to take full effect, so they are usually started alongside another medication that acts more quickly. Regular blood tests are needed to watch for side effects on the bone marrow and liver.

Biologic Therapies

• Anti-TNF agents — infliximab, adalimumab, golimumab, and biosimilar versions
• Anti-integrin agents — vedolizumab, which acts mainly in the gut
• Anti-IL-12/23 and anti-IL-23 agents — ustekinumab, risankizumab, mirikizumab

Biologics are given as injections or intravenous infusions. They are typically used when 5-ASAs, steroids, or immunomodulators have not been enough, or when the disease is moderate to severe from the start. Before starting a biologic, doctors usually screen for infections such as tuberculosis and hepatitis B, because suppressing the immune system can let these reactivate.

Small-Molecule Oral Therapies

Newer oral medicines, including JAK inhibitors (such as tofacitinib and upadacitinib) and S1P receptor modulators (such as ozanimod), are now available for ulcerative colitis and, in some cases, Crohn’s. They offer another option when biologics are not suitable or have stopped working. Each has its own side-effect profile that needs careful discussion.

Antibiotics

Antibiotics such as metronidazole and ciprofloxacin are used in specific situations — for example, in perianal Crohn’s disease with infection, or after certain surgeries. They are not a general treatment for IBD.

Surgery

Surgery is not the first option for IBD, but it has an important role when medication is not enough or complications develop. The role of surgery is different in Crohn’s disease and ulcerative colitis.

Surgery in ulcerative colitis can be curative for the bowel disease itself, because the inflammation is limited to the colon. Removing the colon ends the colitis. Common operations include:

• Total colectomy with ileostomy — the colon is removed and the end of the small intestine is brought out through the abdominal wall as a stoma, with stool collected in a bag
• Proctocolectomy with ileal pouch-anal anastomosis (J-pouch) — the colon and rectum are removed, and a pouch is created from the end of the small intestine and joined to the anus, restoring more normal bowel function over time
• Subtotal colectomy — in urgent situations such as severe flare unresponsive to medical treatment

Even after the colon is removed, regular follow-up is important. Pouchitis (inflammation of the J-pouch) is common, and other complications such as fertility effects in women need to be discussed beforehand.

Surgery in Crohn’s disease is used to treat complications — strictures, fistulas, abscesses, or segments of disease that do not respond to medication. Because Crohn’s can affect any part of the gut, surgery does not cure the disease; inflammation may return at another site or at the join after surgery. Common operations include:

• Segmental bowel resection — removing the diseased section and joining the healthy ends
• Strictureplasty — widening a narrowed segment without removing it, helping to preserve bowel length
• Drainage of abscesses and repair or seton placement for fistulas
• Stoma formation — temporary or permanent, depending on the situation

Operations can be done by open surgery, laparoscopic (keyhole) surgery, or robotic-assisted surgery. The choice depends on disease complexity, prior surgeries, and the experience of the surgical team. Laparoscopic and robotic approaches generally allow smaller incisions and faster recovery for suitable cases, while open surgery may be needed in complex or emergency situations.

Recovery from IBD surgery usually involves a hospital stay of several days, gradual reintroduction of food, and a return to most normal activities over four to eight weeks. If a stoma has been created, a specialist stoma nurse will teach you how to care for it.

Lifestyle and Self-Management

Medication is the backbone of IBD treatment, but day-to-day self-management makes a real difference to how you feel and how stable the disease stays.

Diet and Nutrition

There is no single diet that cures IBD, and no single food that causes flares for everyone. However, nutrition matters in several ways:

• During a flare, many people find a lower-fibre, lower-residue diet easier to tolerate. Soft, cooked foods are often gentler than raw vegetables, nuts, seeds, and skins.
• In remission, a varied, balanced diet is generally encouraged. Restricting foods unnecessarily can lead to weight loss and nutrient deficiencies.
• Food triggers vary from person to person. Keeping a food and symptom diary can help identify what does or does not work for you.
• Exclusive enteral nutrition — a fully liquid feed used for several weeks — is an effective option to induce remission in children with Crohn’s and is sometimes used in adults.
• Nutrient deficiencies are common in IBD. Iron, vitamin B12, vitamin D, folate, calcium, and zinc may need to be checked and replaced.

A dietitian experienced in IBD can be very helpful, especially after surgery, during a flare, or when restrictive diets are being considered.

Smoking

If you have Crohn’s disease and you smoke, stopping smoking is one of the most important things you can do. Smoking worsens Crohn’s, raises the risk of flares, and increases the chance of needing surgery and of disease returning after surgery.

Exercise and Physical Activity

Regular, moderate exercise is helpful for general health, mood, bone strength, and fatigue. During flares, gentler activities such as walking, yoga, or stretching may be more appropriate. There is no need to avoid exercise simply because you have IBD.

Stress and Mental Health

Stress does not cause IBD, but it can worsen symptoms and is a common consequence of living with a chronic condition. Anxiety and depression are more common in people with IBD than in the general population. Talking therapies, mindfulness, and where needed medication, can all help. Tell your gastroenterology team if you are struggling — mental health is part of IBD care, not a separate problem.

Vaccinations and Infection Prevention

Many IBD medications dampen the immune system. Doctors typically recommend keeping vaccinations up to date, including annual influenza vaccination and pneumococcal vaccination. Live vaccines may need to be avoided while on immune-suppressing treatment — check with your specialist before any vaccination. Travel vaccines should be planned well in advance.

Monitoring and Long-term Care

IBD is a lifelong condition, and ongoing monitoring helps catch flares early, watch for medication side effects, and reduce the risk of complications.

Typical elements of monitoring include:

• Regular review with a gastroenterologist, often every 3 to 12 months depending on disease activity
• Periodic blood tests — full blood count, kidney and liver function, inflammation markers, vitamin and iron levels, and drug levels for some medications
• Faecal calprotectin checks to detect inflammation before symptoms return
• Endoscopy or imaging at intervals appropriate to your disease type and history
• Bone density assessment if you have had repeated courses of steroids
• Skin checks, particularly if you are on long-term immune-suppressing therapy, which can raise the risk of certain skin cancers

Complications

Complications can arise from the disease itself, from medications, or from surgery. Recognising them early often leads to better outcomes.

Disease-related complications include:

• Strictures and bowel obstruction (mainly in Crohn’s)
• Fistulas and abscesses (mainly in Crohn’s, including perianal disease)
• Severe flares requiring hospital admission
• Toxic megacolon (a rare but serious complication of severe ulcerative colitis)
• Anaemia and nutrient deficiencies
• Bone thinning (osteopenia and osteoporosis)
• Increased risk of blood clots, especially during flares
• Colorectal cancer with long-standing colonic disease
• Extraintestinal complications affecting joints, eyes, skin, and liver

Medication-related risks vary by drug. Steroids can cause weight gain, mood changes, and bone thinning. Immunomodulators and biologics can increase infection risk and, in some cases, other long-term risks. Your team will weigh these against the benefits of controlling the disease, which carries its own risks if left untreated.

Living with IBD

For many people, the biggest challenge of IBD is not the medical treatment itself but the way the condition fits into daily life — work, relationships, family planning, travel, and emotional well-being.

Work and School

Most people with IBD can work or study, though periods of active disease may require time off. Flexibility — for example, knowing where toilets are, being able to attend medical appointments, working from home during flares — can make a significant difference. Talking to employers or schools about reasonable adjustments is often more helpful than trying to hide the condition.

Relationships and Sexual Health

IBD can affect intimacy, particularly during flares, after surgery, or because of fatigue and body-image concerns. Open conversation with partners and, when needed, with your doctor or a counsellor, is part of good care. Perianal disease and stomas raise their own concerns; specialist nurses are experienced in helping people work through them.

Pregnancy and Fertility

Most people with IBD can have healthy pregnancies. Disease activity at the time of conception influences outcomes, so doctors typically encourage planning pregnancy during a period of stable remission. Most IBD medications, including many biologics, are considered compatible with pregnancy, but specific decisions should be made with a gastroenterologist and obstetrician together, ideally before conception.

Some pelvic surgeries — particularly J-pouch surgery in women — can affect fertility. If this is relevant to you, discuss it with your surgical team in advance, including whether laparoscopic or other approaches might reduce that risk.

Travel

Travel is possible and is something most people with IBD continue to enjoy. Useful steps include carrying a summary of your diagnosis and medications, planning for refrigeration if any of your medications need it, taking extra supplies, arranging travel insurance that covers your condition, and discussing vaccinations before travel.

IBD in Children

About one in four people with IBD is diagnosed in childhood or adolescence. Paediatric IBD shares many features with adult disease but has important differences that need a specialist paediatric gastroenterology team.

Presentation can be different. Children may present with poor growth or delayed puberty as a main sign, sometimes before clear gut symptoms develop. Weight loss, fatigue, and falling behind on growth charts are all reasons for evaluation.

Disease pattern tends to be more extensive at diagnosis in children than in adults, particularly in Crohn’s disease.

Medications used in children are largely the same as in adults, with dosing adjusted for weight and careful attention to long-term safety. Biologics are increasingly used earlier in children with moderate to severe disease.

Psychosocial care matters enormously. School absences, body-image concerns, the visibility of toilet urgency or stomas, and the emotional weight of a lifelong diagnosis can be significant. Paediatric IBD teams typically include psychologists, dietitians, and specialist nurses alongside doctors.

Transition to adult care is an important step. Most centres begin preparing teenagers from around age 14 to take an active role in their own care, with a structured handover to adult services usually completed between ages 16 and 19.

Preventing Flares and Complications

IBD cannot be prevented from developing, but once diagnosed, several steps lower the chance of flares and complications:

• Take medications as prescribed, even when you feel well. Stopping maintenance treatment is a common cause of flares.
• Attend follow-up appointments and complete recommended blood tests and surveillance investigations.
• Avoid unnecessary non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, which can trigger flares in some people. Discuss alternatives with your doctor.
• Stop smoking, particularly if you have Crohn’s disease.
• Address infections promptly, including gut infections that can mimic or trigger a flare.
• Keep vaccinations up to date, in consultation with your specialist.
• Look after mental health, sleep, and stress, which all influence disease activity.

If symptoms return between appointments, contact your team early rather than waiting. Early intervention in a flare is usually easier and uses less medication than waiting until it is severe.

When to Seek Urgent Care

Most IBD flares can be managed by your usual team, but some situations need urgent attention. Seek same-day medical care or go to an emergency department if you have:

• Severe abdominal pain that is constant or rapidly worsening
• A swollen, tender abdomen, especially with fever
• Heavy rectal bleeding or passing large amounts of blood
• Persistent vomiting and inability to keep fluids down
• Signs of dehydration — reduced urine, dizziness, very dry mouth
• Fever above 38.5°C with chills
• Sudden new severe perianal pain or swelling
• Sudden swelling, redness, or pain in a leg (possible blood clot)

If you are on immune-suppressing treatment, fevers and infections deserve a lower threshold for review, because the usual signs of infection may be less obvious.

Frequently Asked Questions

Is IBD curable?

Crohn’s disease is not currently curable, but it can be controlled, often for long stretches at a time. Ulcerative colitis can be effectively cured of its bowel inflammation by surgical removal of the colon, although that is a major decision with its own considerations. For most people, the goal of treatment is long-term remission rather than cure.

Will I need surgery?

Not everyone with IBD needs surgery. Better medications mean fewer people require surgery than in the past, and many never do. When surgery is needed, it is often because of a specific complication or because medications are no longer enough. Decisions about surgery are made together with your gastroenterologist and a surgical specialist.

Can diet alone control my IBD?

For most adults, diet alone does not control IBD. Specific nutritional approaches such as exclusive enteral nutrition can induce remission in Crohn’s disease, especially in children. Diet plays an important supporting role in symptom management and general health for all people with IBD, but it usually works alongside medication rather than replacing it.

Is IBD passed on to my children?

Having IBD raises your child’s risk slightly, but most children of parents with IBD never develop the condition. If both parents have IBD, the risk is higher. Genetic testing is not routinely used because so many genes are involved and the result does not change day-to-day care.

Can I get pregnant safely with IBD?

Yes, most people with IBD can have healthy pregnancies. The best outcomes are seen when the disease is in stable remission at the time of conception. Most IBD medications can be continued safely during pregnancy, but specific decisions should be made with your gastroenterologist and obstetrician before becoming pregnant.

What is a stoma, and will I need one?

A stoma is an opening on the abdomen where the bowel is brought to the skin so that stool can be collected in a bag. Stomas can be temporary, to let an area of bowel heal after surgery, or permanent. Many people with IBD never need a stoma. For those who do, modern stoma care and equipment allow most people to live full, active lives.

Does stress cause flares?

Stress does not cause IBD, but it can contribute to flares and worsen symptoms. Managing stress — through sleep, exercise, social support, and where needed talking therapies — is a useful part of overall care.

Are biologics safe long-term?

Biologics have been in widespread use for more than two decades and have a well-studied safety profile. They do increase the risk of certain infections, and small increases in some other risks have been described. Most specialists view the benefits of controlling moderate to severe IBD as outweighing these risks for the people who need them. Your team will discuss the specific balance for your situation.

Can I drink alcohol?

Modest alcohol intake is generally tolerated by people with IBD in remission, but it can worsen symptoms in some people, particularly during flares. Some medications interact with alcohol — methotrexate, for example, can affect the liver, and alcohol adds to that risk. Discuss your specific situation with your doctor.

Will IBD shorten my life?

For most people with well-managed IBD, life expectancy is close to that of the general population. Risks are higher in people with severe disease, complications, or long-standing colonic involvement, which is why monitoring and surveillance are so important.

Conclusion

Inflammatory bowel disease is a lifelong condition, but it is also a condition that has changed enormously over the past two decades. Better diagnostic tools, a wider range of effective medications, a clearer understanding of how to monitor disease activity, and refined surgical techniques mean that many people with IBD now lead full, active lives with long stretches of remission.

The most important relationship in IBD care is the long-term partnership with your gastroenterology team. Treatment is rarely a single decision; it is a series of adjustments over time, guided by how the disease behaves, how you respond, and what matters most to you in your life. Understanding the condition, taking treatment consistently, watching for changes, and seeking review early when something feels off all add up to a meaningful difference in how you live with IBD over the years.