IBD: From diagnosis and treatment to long-term disease management

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Reference: October 2026 | Issue 10 | Vol 12 | Page 30

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Inflammatory bowel disease (IBD) is a chronic, relapsing and remitting disorder of the gastrointestinal tract, with Crohn’s disease (CD) and ulcerative colitis (UC) representing the two forms. Although both conditions are characterised by dysregulated and sustained intestinal inflammation, they differ considerably in their anatomical distribution, pathological characteristics, clinical presentation, and potential complications. IBD can occur at any age, but is frequently diagnosed during adolescence and early adulthood, often at a stage of life when education, employment, relationships, fertility, and social development are particularly important.

The management of IBD has changed considerably over recent decades. Treatment has moved from an emphasis on controlling symptoms towards a more proactive approach aimed at controlling intestinal inflammation, achieving sustained remission, preventing structural bowel damage and reducing the risk of hospitalisation and surgery. This shift has been accompanied by major advances in pharmacological treatment, including the increasing use of biologic therapies and targeted small molecules.

Current European guidance emphasises individualised treatment, objective assessment of disease activity, and close monitoring of treatment response.^{1,2, 3} The 2024 European Crohn’s and Colitis Organisation (ECCO) guideline provides updated recommendations for the medical treatment of Crohn’s disease, while the 2026 ECCO guideline provides an updated evidence base for medical treatment of ulcerative colitis.^1,2

CD and UC

CD can involve any part of the gastrointestinal tract, from the mouth to the anus, with the terminal ileum and colon among the most frequently affected sites. The inflammatory process is typically transmural and discontinuous, with affected segments of bowel separated by areas of relatively normal-appearing tissue. This characteristic distribution contributes to the complications associated with CD, including strictures, fistulae, abscesses, and penetrating disease.^1,4

UC is confined to the colon and characteristically involves the rectum, extending proximally in a continuous pattern. Inflammation principally affects the mucosa and may extend into the submucosa in more severe disease. The extent of ulcerative colitis is commonly described according to whether the disease is limited to the rectum, extends through the left side of the colon or involves more extensive areas of the colon.^2,5

The distinction between the two diseases is clinically important, although symptoms frequently overlap. UC commonly presents with bloody diarrhoea, increased stool frequency, urgency, and tenesmus, whereas CD may present with abdominal pain, diarrhoea, weight loss, fatigue, nutritional deficiencies, or symptoms associated with stricturing or penetrating disease. Some patients, however, present with relatively non-specific symptoms, and the diagnosis cannot be established from symptoms alone.^4,5

The precise cause of IBD remains incompletely understood. It is considered to result from an interaction between genetic susceptibility, environmental influences, intestinal microbiota, and dysregulation of the immune response. IBD should not be regarded as a condition caused simply by stress or diet. Nevertheless, environmental factors, smoking, nutrition, psychological wellbeing, and lifestyle can influence disease experience and management.^1,2

Recognising possible IBD

Early recognition of IBD is important because persistent untreated intestinal inflammation can result in cumulative bowel damage and disability. Contemporary management places considerable emphasis on early diagnosis and appropriate assessment.¹ Persistent or recurrent diarrhoea, rectal bleeding, abdominal pain, nocturnal bowel symptoms, urgency, tenesmus, unexplained weight loss, and persistent fatigue should prompt consideration of an underlying inflammatory gastrointestinal disorder. Anaemia, particularly iron-deficiency anaemia without an obvious explanation, may provide an additional clue.^1,2

A detailed clinical history should identify the duration and progression of symptoms, stool frequency, stool consistency, the presence and quantity of blood, urgency, nocturnal symptoms, and abdominal pain. It is important to establish whether the patient has experienced weight loss, anorexia, or reduced dietary intake and whether symptoms are affecting attendance at work, college, or social activities.⁴

Medication history is particularly relevant. Non-steroidal anti-inflammatory drugs (NSAIDs) may exacerbate gastrointestinal symptoms in some patients, while the recent use of antibiotics raises the possibility of infectious diarrhoea, including Clostridioides difficile. A history of recent travel, gastrointestinal infection, family history of IBD, and previous episodes of unexplained gastrointestinal symptoms should also be explored.^4,5

In a patient with established IBD, a change in symptoms should not automatically be attributed to an inflammatory flare. Infection, medication adverse effects, irritable bowel syndrome, bile acid diarrhoea, small intestinal bacterial overgrowth, and other gastrointestinal conditions can produce symptoms resembling active IBD. Objective assessment is therefore essential before treatment is escalated.^1,2

Diagnosis and investigation

There is no single diagnostic blood test for IBD. Diagnosis requires integration of clinical history, laboratory investigations, stool assessment, endoscopy, histology, and, where appropriate, cross-sectional imaging.⁶

Initial blood investigations commonly include a full blood count, inflammatory markers, renal function, electrolytes, liver function, albumin, and iron studies. Vitamin B12 and folate may be particularly relevant in patients with CD involving the terminal ileum or those with nutritional compromise.

Vitamin D status may also warrant assessment, depending on the individual clinical situation.⁶ C-reactive protein (CRP) can provide useful information regarding systemic inflammation, although it is not sufficiently sensitive or specific to be used alone to diagnose or exclude active IBD. Some patients with significant intestinal inflammation may have a relatively normal CRP, while other inflammatory or infectious conditions can result in an elevated result.⁶

Faecal calprotectin has become an important non-invasive investigation. It is a marker of intestinal inflammation and can assist in distinguishing IBD from functional disorders such as irritable bowel syndrome.⁶ An elevated result, however, is not specific for IBD and may occur with gastrointestinal infection, colorectal neoplasia, NSAID use, and other inflammatory conditions. Interpretation must therefore take place within the clinical context.

Endoscopic assessment remains central to diagnosis. Colonoscopy with assessment of the terminal ileum and appropriate biopsies can demonstrate the distribution and severity of inflammation and provides tissue for histological examination. Histology is important in establishing chronicity and supporting the distinction between IBD and other causes of colitis.⁶

Imaging has particular importance in CD because inflammation may involve areas of small bowel that cannot be adequately assessed by conventional colonoscopy. Magnetic resonance enterography and intestinal ultrasound are increasingly important in assessing bowel inflammation, strictures, fistulae, and other complications. Contemporary diagnostic guidance increasingly recognises the value of non-invasive biomarkers and intestinal ultrasound in monitoring disease activity and reducing unnecessary invasive investigations.⁷

From symptom control to treat-to-target management

One of the most important developments in modern IBD care has been the recognition that symptoms alone do not provide a sufficient measure of disease control. A patient may feel relatively well despite ongoing objective intestinal inflammation, while another may experience significant gastrointestinal symptoms despite little evidence of active disease.⁸

The STRIDE-II treat-to-target framework established a structured approach to defining treatment goals in IBD.^3,8 Short-term objectives include improvement in symptoms and restoration of normal functioning, while intermediate and long-term goals include normalisation of inflammatory biomarkers and endoscopic healing. The overall objective is not simply for the patient to feel better temporarily, but to achieve sustained control of the inflammatory process and reduce the risk of future bowel damage.^3,8

This approach has important implications for nursing assessment. A patient’s current symptoms should be compared with their usual baseline. Stool frequency, rectal bleeding, urgency, abdominal pain, nocturnal symptoms, weight, fatigue, and functional capacity should all be considered alongside objective investigations.^6,8

The concept of remission should be explained carefully to patients. Symptomatic improvement is important, but it does not necessarily mean that intestinal inflammation has completely resolved. Explaining this distinction can improve understanding of why patients may need ongoing medication and monitoring even when they feel well.^6,8

Pharmacological management

Treatment is individualised according to disease type, anatomical location, disease activity, previous treatment response, prognostic factors, complications, and patient preferences. The therapeutic approach also differs between CD and UC.^1,2

In mild-moderate UC, 5-aminosalicylates (ASA), particularly mesalazine, remain an important treatment option. Oral and rectal preparations may be used according to disease distribution, and combination therapy may be appropriate where disease extends beyond the rectum.² The 2026 ECCO guideline continues to support the use of 5-ASA in appropriate patients with mildly-moderately active UC.² In contrast, the role of 5-ASA in CD is very limited. The 2024 ECCO guideline recommends against the use of 5-ASA for induction or maintenance of remission in CD because of insufficient evidence of meaningful efficacy.¹

Corticosteroids remain valuable for inducing remission in selected patients with active disease, particularly where rapid control of inflammation is required. Their use should, however, be limited because of their substantial short- and long-term adverse effect profile. Prolonged corticosteroid exposure is associated with osteoporosis, infection, hyperglycaemia, hypertension, weight gain, mood disturbance, cataracts, and adrenal suppression.

Steroids should therefore generally be regarded as an induction or bridging treatment rather than a long-term maintenance strategy.^1,2 Repeated courses of corticosteroids should prompt consideration of whether the patient’s treatment strategy requires review. A patient who repeatedly relapses when corticosteroids are reduced may require steroid-sparing therapy rather than repeated courses of the same treatment.^1,2

Immunomodulators such as azathioprine and mercaptopurine continue to have a role in selected patients, although their use has changed as biologic and targeted therapies have become increasingly available. Treatment requires appropriate laboratory monitoring and patient education concerning infection, adverse effects, and the importance of reporting concerning symptoms.^1,2

Biologic therapies have transformed the management of moderate to severe IBD. Anti-tumour necrosis factor therapies, anti-integrin agents, and interleukin-targeted therapies may be used according to the individual clinical circumstances. Targeted small molecules, including Janus kinase inhibitors and other advanced therapies, have further expanded the treatment options available to patients with moderate to severe disease.^1,2

The choice of therapy is no longer simply a decision about which medication is most effective. It may involve consideration of previous treatment exposure; comorbidities; safety, route, and frequency of administration; patient preference; pregnancy considerations; lifestyle; adherence; and the individual’s risk of disease progression.^1,2

Infection prevention

Infection prevention is an important component of IBD management, particularly for patients receiving immunosuppressive or advanced therapies. The updated ECCO guidance on infections in IBD provides recommendations concerning infection prevention, screening, and vaccination.⁹ Vaccination status should be reviewed proactively rather than waiting until immunosuppressive treatment is commenced. Where possible, vaccination assessment should take place before significant immunosuppression begins, because some live vaccines may be contraindicated during immunosuppressive therapy.⁹

Influenza, Covid-19, pneumococcal, hepatitis B, and other vaccinations should be considered according to the individual’s age, risk factors, treatment, and national recommendations.⁹ The precise vaccination programme should be determined in accordance with current Irish immunisation guidance and the patient’s clinical circumstances.

Nutritional assessment and anaemia

Nutritional problems are common in IBD and may arise from reduced oral intake, intestinal inflammation, malabsorption, increased nutritional requirements, or self-imposed dietary restriction.^1,2,10 Iron-deficiency anaemia is particularly important. It may contribute substantially to fatigue, reduced concentration, and impaired quality of life. Iron deficiency may occur in the presence or absence of anaemia and inflammatory activity can complicate interpretation of ferritin.

Assessment therefore requires consideration of the full clinical picture and relevant laboratory parameters.^1,2 Vitamin B12 deficiency is particularly relevant in CD involving the terminal ileum and following ileal resection. Folate, vitamin D, and other micronutrients may also require assessment according to the individual’s disease and nutritional status.^1,10

Patients frequently modify their diet in an attempt to control symptoms. Some may unnecessarily exclude dairy products, fibre, gluten, or multiple other foods, resulting in an increasingly restrictive diet. Contemporary ECCO guidance supports personalised dietary management rather than a universal diet for all patients with IBD.¹⁰

Extraintestinal manifestations

Extraintestinal manifestations of IBD can involve the joints, skin, eyes, liver and biliary system.¹¹ Musculoskeletal manifestations include peripheral arthritis and axial spondyloarthritis. Patients may describe persistent inflammatory back pain, morning stiffness, or painful swollen joints. Dermatological manifestations include erythema nodosum and pyoderma gangrenosum, while ocular manifestations include episcleritis and uveitis.¹¹ The distinction between these conditions and unrelated symptoms is clinically important. Acute painful red eye, photophobia, or visual disturbance, for example, warrants urgent ophthalmological assessment because uveitis can threaten vision.¹¹

Primary sclerosing cholangitis is an important hepatobiliary association with IBD and is particularly associated with UC. Abnormal liver function tests should therefore not automatically be attributed to medication or alcohol without appropriate clinical consideration.¹¹ Venous thromboembolism is another important consideration, particularly during active disease and hospitalisation. The inflammatory state associated with IBD can increase thrombotic risk, reinforcing the importance of appropriate assessment and prophylaxis in patients who require hospital admission.¹¹

Acute severe UC

Acute severe UC represents a potentially life-threatening complication and requires urgent hospital-based management. Patients may present with frequent bloody diarrhoea, systemic toxicity, fever, tachycardia, anaemia, elevated inflammatory markers, dehydration, and electrolyte disturbance.¹² Changes in stool frequency, rectal bleeding, abdominal pain, abdominal distension, temperature, pulse, blood pressure, hydration status, and overall clinical condition should be carefully monitored.¹²

Potential complications include severe dehydration, electrolyte abnormalities, significant anaemia, toxic megacolon, perforation, sepsis, and venous thromboembolism. Failure to respond appropriately to medical treatment may necessitate rescue therapy or colectomy.¹² Acute severe colitis can be frightening and upsetting, particularly when patients are experiencing frequent bloody stools and urgency. Maintaining privacy, dignity, and clear communication is an important component of care.

Complicated CD

CD may result in stricturing, penetrating, or fistulising complications. A patient with a known history of CD who develops worsening abdominal cramping, distension, vomiting, or inability to pass stool or flatus requires urgent clinical assessment because these symptoms may indicate intestinal obstruction.⁴

Perianal CD can be particularly challenging. Patients may experience pain, drainage, abscess formation, fistulae, and significant psychological distress. Management frequently requires close collaboration between gastroenterologists, colorectal surgeons, radiologists, specialist nurses, and other members of the multidisciplinary team.⁴ The 2024 ECCO surgical guideline emphasises multidisciplinary management of complicated CD and the importance of controlling sepsis before immunosuppressive treatment is undertaken in patients with septic complications.⁴

Perianal disease may be associated with embarrassment and reluctance to disclose symptoms, making a trusting therapeutic relationship particularly important.

Colorectal cancer

Long-standing colonic inflammation is associated with an increased risk of colorectal neoplasia. Risk is influenced by factors including disease duration, extent of colonic involvement, inflammatory burden, family history, and associated conditions.¹³ Surveillance colonoscopy is an important element of long-term care for selected patients with colonic IBD. Modern surveillance increasingly focuses on high-quality colonoscopy, careful mucosal assessment, and identification of dysplasia.¹³ The updated British Society of Gastroenterology guideline on colorectal surveillance in IBD provides contemporary recommendations regarding surveillance strategies and dysplasia detection.¹³

Repeated colonoscopy can be burdensome for patients and may contribute to anxiety, discomfort, and reluctance to undergo further surveillance. Patients should be educated on why surveillance is necessary, addressing concerns about bowel preparation and sedation, and ensuring that patients understand the difference between routine monitoring, and investigation of new symptoms.

Psychological wellbeing

The psychological impact of IBD can be substantial. Patients may experience anxiety, depression, fatigue, altered body image, embarrassment, fear of incontinence, sexual difficulties, and social isolation. Young adults may particularly struggle with the unpredictability of bowel symptoms and the effect of disease on education, employment, relationships, and social activities.^11,14 The practical burden of urgency should not be underestimated. Patients may plan journeys around access to toilets, avoid eating before leaving home or restrict participation in social events because of fear of an accident. Such experiences may not be identified unless specifically explored.¹⁴

A holistic assessment should therefore extend beyond questions about bowel frequency. Asking how the illness is affecting the patient’s education, employment, relationships, sleep, sexual health, confidence, and social life can reveal problems that may otherwise remain hidden.¹⁴ Mental health support should be regarded as part of comprehensive IBD management rather than an optional addition to gastrointestinal care.^11,14

Shared decision-making

Adherence is particularly challenging in chronic relapsing diseases. A patient who feels well may question the need for ongoing medication, particularly when treatment has adverse effects or requires regular injections or infusions.^1,2 It is important for patients to understand that clinical remission does not necessarily mean the absence of underlying inflammation. The purpose of maintenance treatment is to sustain disease control and reduce the risk of relapse and complications.^1,3,8

Shared decision-making is increasingly important because several effective advanced therapies may be available for an individual patient. Treatment decisions should incorporate evidence of effectiveness and safety alongside the patient’s circumstances and preferences. The patient’s lifestyle, work commitments, travel, injection preferences, fertility plans, and willingness to attend hospital-based treatment may all influence the most appropriate choice.^1,2 This approach recognises the patient as an active participant in treatment rather than a passive recipient of medical intervention.

Fertility, pregnancy, and sexual health

Fertility and reproductive health should be an integral part of routine IBD care. These discussions should be individualised, sensitive and non-judgemental, with appropriate involvement of the relevant specialist team to support informed decision-making and continuity of care.^1,2,5 Patients may be reluctant to raise concerns about fertility, sexual health, or pregnancy, particularly when these issues are sensitive or difficult to discuss. It is important to initiate these conversations in a sensitive, non-judgemental manner and ensure that appropriate advice, information, and referral are provided.⁵

Active IBD can adversely affect pregnancy outcomes, while individual medications require careful consideration when planning conception and throughout pregnancy. However, discontinuing effective treatment unnecessarily may precipitate a disease flare, which can present greater risks to both the patient and pregnancy than continuing appropriate therapy. It is important to reinforce the value of maintaining disease control when planning pregnancy.^1,2,5

Women and men of reproductive age should have opportunities to discuss fertility, contraception and pregnancy planning as part of routine IBD care. This is particularly relevant in primary care because contraception and sexual health consultations may provide an opportunity to identify gastrointestinal symptoms, medication concerns or reproductive health questions that have not previously been discussed.

Patient education

Patient education should be individualised and revisited throughout the disease course, reflecting changes in treatment, disease activity, and the patient’s circumstances. Patients should understand their diagnosis, treatment plan, monitoring programme, and the symptoms or changes that warrant clinical review. Education is particularly important in supporting patients to recognise the difference between expected day-to-day variation and changes that may indicate active disease.¹⁴

Education should also equip patients with practical skills for self-management. Patients benefit from understanding their usual bowel pattern, recognising changes from their baseline, and knowing when to contact their IBD team. Written information supported by personalised flare management plans can help patients identify early changes in their condition, understand appropriate actions, and seek timely clinical advice.¹⁴

Effective education should be delivered in a manner that reflects the patient’s health literacy, preferences, and individual circumstances. Providing written information alone does not ensure that it has been understood or can be applied in practice. Clinicians should encourage questions, use clear and accessible language, check understanding, and address misconceptions, particularly around diet, medication adherence, and the relationship between symptoms and underlying inflammation. This approach supports informed decision-making, strengthens self-management, and enables patients to take a more active role in managing their condition.¹⁴

Conclusion

IBD is a complex chronic condition requiring long-term, multidisciplinary management. The contemporary approach is no longer focused solely on relieving diarrhoea, abdominal pain, or rectal bleeding. Instead, treatment aims to achieve sustained control of inflammation, prevent progressive bowel damage, minimise corticosteroid exposure, reduce complications, and enable patients to maintain their quality of life.

Recognition of IBD symptoms, appropriate investigation, and timely referral can influence the patient’s subsequent disease trajectory. In established disease, careful assessment of symptoms alongside objective markers of inflammation can help distinguish genuine relapse from other causes of gastrointestinal symptoms. Patients should be monitored for treatment-related complications, nutritional deficiencies, psychological distress, and difficulties with adherence.

Optimal care requires an understanding that the impact of the disease extends well beyond the bowel. For many patients, the greatest burden may be the unpredictability of symptoms, the fear of urgency or incontinence, the disruption to education and employment, concerns about relationships and fertility, or the psychological impact of living with a chronic disease.

Modern IBD care requires clinical expertise, proactive disease management and person-centred care. From early recognition and evidence-based assessment through treatment, monitoring, and long-term management, healthcare professionals must support patients across the full course of CD and UC. Individualised education, proactive monitoring, timely identification of deterioration, and continuity of care help to optimise disease control, reduce the risk of complications, and support informed decision-making. Patients should be provided with consistent support throughout the disease journey to achieve the best possible health outcomes and quality of life while living with IBD.