Dr Ehinomen Imoisili, Dr Sabyasachi Chowdhury, Dr Sally Buxton
13 year old Theo was referred to paediatric outpatients by his GP. He comes to see you in clinic with his mum, Angie. Theo has had diarrhoea and abdominal pain on and off for two years, and in the past six month, there has also sometimes been blood in his poo.
The GP had sent off bloods and a stool sample; Theo’s CRP is 55 and he has a high faecal calprotectin level of 310.
He looks pale and he has a soft, but diffusely tender abdomen. You’re worried he might have inflammatory bowel disease.
Let’s take this case further and think about IBD, how it is investigated, diagnosed and managed.
What is IBD?
Inflammatory bowel disease is an autoimmune condition that causes inflammation of the gut. Depending on the type, IBD can affect any part of the gut, from the mouth to the anus.
Classification
There are two main ways we can classify IBD; either based on the pattern of disease and its histology, or on the age of the patient
| Crohn’s disease | Ulcerative colitis | IBD unclassified |
| Inflammation can affect the whole bowel wall | The inflammation is limited to the inner part of the bowel wall (the mucosa). | Some patients do not quite fit in either category |
| Can affect anywhere from mouth to anus | Only affects the colon and rectum |
Based on the age of the patient, IBD can be classified as
- Neonatal IBD; diagnosed within first 28 days of life.
- Infantile IBD; diagnosed in children under 2 years old.
- Very Early Onset IBD; diagnosed before the age of 6
- Paediatric-Onset IBD; onset of disease before 17 years of age.
The younger the child is, the more uncommon IBD is. Anyone under the age of 6 with an IBD diagnosis should have their immunology and genetics tested (there are reported links with primary immunodeficiency). Also, you may well pick up single gene defects in these younger patients, which might need specific treatments.
Why does IBD develop?
We don’t know exactly why IBD develops, but two of the important factors are likely to be genetics, and environmental factors. To put it really simply, IBD probably happens because of an abnormal immune response to ‘normal’ environmental factors, in someone who has genes which make them more susceptible to IBD.
That’s why it’s so important in the history to ask about:
- Family history– if there is a family history of any autoimmune condition (think type 1 diabetes, coeliac disease, psoriasis, etc), this increases the risk of IBD
- Genetic disorders– IBD is associated with Turner syndrome and glycogen storage disease type 1B
- Cigarette smoking (hopefully not too relevant in most of our paediatric patients)- this increases risk of Crohn’s disease but is protective for UC.
Other risk factors to remember are:
- Regular antibiotic exposure early in life increases risk. Yet another reason for us to be good antibiotic stewards.
- Western diet is thought to increase risk (more fatty foods).
Have a think about which of the factors listed above are modifiable and which are not.
Symptoms of IBD
These are the things you should be alert for in your history and examination:
- Abdominal pain
- Diarrhoea
- Blood and/or mucus in stools
- Pallor
- Lethargy
- Extra-intestinal features: erythema nodosum, pyoderma gangrenosum, joint pain, hepatitis, pancreatitis, uveitis
Some clinical features can help you to figure out which type of IBD is more likely –
| Ulcerative Colitis | Crohn’s Disease |
| Bloody diarrhoea more common | Mouth ulcers |
| Stool urgency | Perianal fistulae |
| Tenesmus (feeling the need to open bowels, but nothing comes out) | Weight loss |
| Fatigue |
Diagnosis
‘An easy way to think about testing for IBD is blood, poo, lights and camera.’
Blood tests
Inflammatory markers- C Reactive Protein, ESR are often high. Anaemia- particularly iron deficiency anaemia, (the absorption of iron is reduced in inflamed bowel). Platelets- high platelets (thrombocytosis) can occur as another marker of inflammation
Liver function tests- liver function might be affected as an extraintestinal effect or albumin might be low, a reflection of the poor nutritional status as a consequence of IBD.
It’s not clear exactly why the liver is affected by IBD; it could simply be that there is a co-existing autoimmune liver disease. Intestinal inflammation might also come along with its own baggage such as portal vein thrombosis; or absorption and metabolic problems such as cholelithiasis and non-alcoholic fatty liver disease.
Even when the kids are started on treatment, don’t forget that some of the medications such as 5-ASA and methotrexate are not very liver-friendly.
Stool tests
Faecal calprotectin levels will be above 250ug/g in active IBD.
Stool culture – it’s really important to rule out infective colitis.
Imaging
Abdominal ultrasound– might show some inflammation in the bowel.
Abdominal X-rays- featureless bowel on imaging can suggest IBD, but XR would normally done to rule out acute emergencies (such as perforation), rather than to diagnose IBD
MRI- good for defining small or large bowel inflammation. MRI is also useful to see the extent of fistulas, and perianal disease.
Endoscopy
- Oesophago-gastro-duodenoscopy (OGD) and ileo-colonoscopy (or, if you’d like less of a of a tongue twister), upper and lower GI endoscopy. Endoscopy is the gold standard in diagnosing IBD because the bowel can be visualised, and biopsies can be taken.
This is what the endoscopist will be looking for:
Crohn’s disease: ‘Cobblestone’ gut appearance, small bowel or colonic granulomas, segmental colitis, ileal stenosis.
Ulcerative colitis: gastritis, diffuse continuous colonic disease involving the rectum, superficial ulcers, crypt abscess.
Wireless capsule endoscopy: This is a newer, non-invasive technique that is suitable for some patients – swallowing a tiny capsule containing a video camera that can transmit images of the small bowel (those of us of a certain age are probably imagining something like the adventures of the Magic School Bus…. If this makes no sense to you, congratulations, you are definitely Gen Z or younger 😉
Management
When treating patients with IBD, we think about two stages of the treatment: induction and maintenance.
Induction therapy: this is the first part of treatment, aiming to induce ‘remission’ (healing of the mucosa). When faecal calprotectin levels are back to normal, this is a good sign remission has been achieved.
Maintenance therapy: self-explanatory – the goal is to ‘maintain’ good disease control.
Exclusive Enteral Nutrition (EEN): this is the first-line induction therapy in mild IBD. This involves stopping regular foods and placing the patient on specially formulated liquid diet for a few weeks (6-12 weeks). As you can imagine, this is tough, so the child may be allowed to have clear fluids as well.
Steroids: high dose intravenous steroids such as methylprednisolone or de-escalating doses of oral steroids such as prednisolone or budesonide can be used as alternative induction therapies.
Amino salicylates (ASA): Such as mesalazine. May be more effective in mild terminal ileal or colonic disease as induction therapy. Also available as suppositories.
Immunomodulators: azathioprine, 6-mercaptopurine, methotrexate. These drugs are mostly used as second-line therapies, particularly when the steroids haven’t worked, or the patient seems to be dependent on steroids to control their IBD. Immunomodulators take 3-4 months to work, so we do need to use some of the more fast-acting drugs alongside them to start with.
Anti-TNF medications: infliximab, adalimumab. These are very effective as induction or maintenance therapy, from mild to severe IBD.
Others: for unresponsive cases of IBD, Vedolizumab (a monoclonal antibody) and Tofacitinib (a JAK inhibitor) are newer drugs available for treatment.
for many of the biologics used for treating IBD, either for adjusting treatment doses or monitoring for side effects.
Surgical interventions: while surgery is a last resort, partial or total colectomy might be necessary in severe or unresponsive cases of IBD. Other surgical options might include a defunctioning colostomy, partial bowel resection, and perianal fistula management strategies such as a seton (a piece of surgical thread to keep a fistula open and draining, while it heals).
Antibiotics – metronidazole for infective flares
Other supportive treatments: IBD can have a huge psychological impact on a young person and their whole family – they might have long hospital stays, unpredictable flare ups of their disease, and have difficult symptoms to manage at home and at school. Not to mention those who have had major surgery, and may have a temporary or permanent stoma.
Summary of treatment options
Induction
| UC | Crohns |
| Steroids (oral/IV) | EEN (Oral) |
| Infliximab (IV) | Steroids (oral/IV) |
| 5-ASA (oral/rectal) | Infliximab (IV) |
Maintenance
| UC | Crohns |
| 5-ASA (oral/rectal) | Azathioprine (oral) |
| Azathioprine (oral) | 6 mercaptopurine (oral) |
| Infliximab (IV) | Methotrexate (oral/SC) |
| Adalimumab (SC) | Infliximab (IV) |
| Vedolizumab (IV) | Adalimumab (SC) |
| Surgery | Vedolizumab (IV) |
Theo had an urgent endoscopy which showed pancolitis. He was started on steroids which brought his IBD into remission, and remained on mesalazine for maintenance therapy.
Key learning points
- Inflammatory bowel disease (classified mainly as Crohns or Ulcerative Colitis) is an autoimmune condition – immune dysregulation leads to gut inflammation in genetically susceptible people.
- IBD is becoming more common in the paediatric population, possibly due to environmental influences that are altering gut microbiomes.
- Gold standard of diagnosis is endoscopy
- Treatments range from EEN, steroids, to biologics, depending on disease severity.
- Management is multidisciplinary.
Further reading
- Van Rheenen PF, Aloi M, Assa A, et al. The Medical Management of Paediatric Crohn’s Disease: an ECCO-ESPGHAN Guideline Update.
- Turner, D, Levine A, Escher JC, et al. Management of Pediatric Ulcerative Colitis: Joint ECCO and ESPGHAN Evidence-based Consensus Guidelines
Authors
Ehinomen Imoisili, ST4 Paediatric registrar; Sabyasachi Chowdhury, ST2 Paediatric doctor, Great North Children’s Hospital, Newcastle-upon Tyne
Expert reviewer – Dr Sally Buxton, Consultant Paediatric Gastroenterologist, Great North Children’s Hospital, Newcastle-upon Tyne