Digestive issues: When to investigate and how to treat

Dawn O’Shea looks at the times a GP should do further testing on patients with gut issues

The Spring Vhi 360 Hot Topics GP webinar looked at a common and complex area in general practice – digestive issues, particularly when to investigate and when to treat. The expert panel, which included consultant gastroenterologist, Dr Orlaith Kelly, along with registered dieticians, Sarah Keogh and Lydia Hendy, provided practical advice on managing a wide range of clinical presentations, including inflammatory bowel disease (IBD) and irritable bowel disease (IBS).

Dr Orlaith Kelly, IBD lead at Connolly Hospital and the Bon Secours Glasnevin, provided a practical toolkit for the investigation and treatment of diarrhoea.

Dr Kelly pointed out that chronic diarrhoea is defined as loose, frequent stools for more than four weeks. She advised that the first step in evaluating a patient with chronic diarrhoea should be to out-rule an infection.

She also reminded attendees that rectal bleeding in a patient >40 years requires a priority one colonoscopy.

She added that faecal immunochemical testing (FIT) is important and a positive FIT result is a good indication for colonoscopy.

High faecal calprotectin suggests the presence of acute or active inflammation. Dr Kelly pointed out that there is a caveat in the interpretation of faecal calprotectin positivity, as it can indicate both infection and inflammation. However, she said it is ‘a really useful test for trying to differentiate between irritable bowel syndrome and inflammatory bowel disease, especially in the younger population’.

High faecal calprotectin in a teenager may warrant referral for further investigation. In IBD, this test can also serve as a therapeutic follow-up marker. A positive result is often associated with clinical relapse and can indicate a flare before symptoms develop.

Recent research suggests that the incidence of coeliac disease in Ireland is in the region of two per 100 population and one in 10 in families, but 75 per cent of patients go undiagnosed

She cautioned that there is a long list of conditions that may cause a rise in faecal calprotectin, including gastroenteritis, colorectal cancer, and gastro-oesophageal reflux disease (GORD). The use of NSAIDs and PPIs can cause a slight rise, and levels can also increase in pregnancy.

Imaging may provide further information in identifying the cause. Dr Kelly recommended intestinal ultrasound, if available, or MRI of the small bowel.

For a comprehensive guide of the diagnosis of chronic diarrhoea, she directed GPs to the British Society of Gastroenterology guideline for the investigation of chronic diarrhoea in adults, which was published in Gut in 2018. The guideline recommends that persistent bloody diarrhoea in patients <40 years requires urgent sigmoidoscopy. Patients <40 with isolated rectal bleeding can have a routine sigmoidoscopy. Patients <40 with persistent watery diarrhoea and raised markers or other risk factors should have a priority one colonoscopy.

Initial blood work should include FBC, ferritin, CRP, thyroid function and coeliac serology. Stool tests should include tests for C. difficile, ova, cysts and parasites, and consideration should be given to FIT. If there is suspicion for cancer or inflammation, the recommendation is for colonoscopy with or without ileoscopy and biopsies. MR enterography or capsule endoscopy is advised where small bowel IBD is suspected.

“Iron, B12, folate, calcium and albumin testing are all very worthwhile. Something we’re less likely to do is assess for immunodeficiencies. It is worth looking for risk factors for HIV, for instance, or to check immunoglobulins,” Dr Kelly added.

Other common disorders that can masquerade as IBD or IBS include bile acid diarrhoea. This requires faecal bile acid testing, which is unfortunately not widely available in Ireland.

“Often we end up starting a trial of treatment with cholestagel or cholestyramine. It can be super useful for patients with bile acid diarrhoea,” Dr Kelly said.

Other conditions to consider are microscopic colitis, malabsorption, post-radiation diarrhoea, fistulas and hormone secreting tumours.

For patients with diarrhoea-predominant IBS (IBS-D) or functional diarrhoea, lifestyle and dietary modification is key. First-line medications for these patients include loperamide, anticholinergics and ondansetron.

Typically these drugs improve diarrhoea in 50-80 per cent of patients.

The management of IBD is more complex, Dr Kelly remarked. Key treatments for moderate-severe disease are anti-TNF alpha antagonists, anti-integrin therapy, JAK inhibitors and IL12/23 inhibitors. In mild-moderate ulcerative colitis (UC), topical and oral 5-ASA agents are advised, with topical steroids used for flares.

Mild-moderate Crohn’s disease can be treated with budesonide, with topical steroid for flares, and/or gut-specific biologics.

Sarah Keogh is a CORU registered dietitian working with the Coeliac Society of Ireland. In her presentation, she provided clarification on the management of different diet-related conditions.
She advised that, for patients presenting with bloating and constipation, the first thing to look at is fibre intake.

“Currently, in Ireland, around 79 per cent of adults don’t eat enough fibre,” Ms Keogh said. A big contributor to this figure is that there is a lot less fibre in foods than people think, she explained.

“We talk about needing a minimum of 25g of fibre a day for adults, but if you look at something like a bowl of porridge, it has 3g of fibre. Two Weetabix has 4g of fibre in it,” Ms Keogh said. “It is about getting fibre at every meal.”

“The key thing to emphasise to the patient is that they need to gradually increase [their fibre intake] over a month,” she stressed. “If after three or four weeks they’re getting nowhere, then we’re going to look at something else.”

Ms Keogh also spoke about lactose or dairy intolerance, the predominant symptoms of which are bloating and flatulence.

“The problem at the moment is that it’s very popular to cut out dairy for every single problem that shows up, and it’s an issue because dairy is an entire food group. Apart from being very, very important for calcium, it’s the major source of iodine in the Irish diet,” she explained. “So a blanket ban on dairy is something we need to be really, really cautious about when we’re looking at total health for patients.

But lactose intolerance is relatively common. In Ireland, around 10 per cent of people have lactose intolerance. But someone with lactose intolerance doesn’t need to cut it out; they just need to reduce it,” she said. Foods with high lactose content include custard, ice cream, ands pancakes made with milk.

She also highlighted that 24 per cent of people with lactose intolerance have coeliac disease as the latter causes a temporary lactose intolerance. Hence, Ms Keogh said, it is very important to check for this condition.

Recent research suggests that the incidence of coeliac disease in Ireland is in the region of two per 100 population and one in 10 in families, but 75 per cent of patients go undiagnosed.

CD is now known to have a broader range of symptoms that was previously thought. Ms Keogh stressed that 40 per cent of CD patients have few, if any, gut symptoms. Bloating is often present but diarrhoea is much less common than previously thought and, in fact, CD patients are more likely to have constipation. Less than 13 per cent of adults with CD have weight loss.

“When I was at university about 30 years ago, CD was diarrhoea, weight loss, and stomach pain. Now we know it is much, much broader,” she said.

One in three CD patients has nervous system involvement, with symptoms including anxiety and depression, as well as loss of balance and coordination. About 25 per cent of people with CD report severe headaches.

Other symptoms include short stature and later puberty. It is also worth remembering that around 40 per cent of people with recurrent iron deficiency anaemia have CD. Low vitamin B12 or low folate should trigger a CD test, Ms Keogh advised.

Skin rashes are also common, including dermatitis herpetiformis, which often turns up on the outside of both elbows, the outside of both knees or the outside of both buttocks. But it can turn up anywhere in the body. Psoriasis is also more common in people with CD.

Regarding clinical assessment for CD, Ms Keogh stressed that three to 10 per cent of people with CD will test negative for CD on tTg testing.

Even if the test is negative, GPs should continue to investigate for CD is suspicion is high or there are other factors such as family history or iron deficient anaemia.

Diagnosis requires blood tests and biopsy. Patients must be eating gluten for at least six weeks before endoscopy.

Information
Vhi is currently undertaking a GP pilot to look at point-of-care faecal calprotectin testing. Expressions of interest are being invited for GPs.

To register, email project manager, Laura Harmon at laura.harmon@vhi.ie.

Vhi 360 Hot Topics is a series of educational webinars focused on key subjects of interest to support the primary care healthcare workforce in delivering improvements to patient care in primary care settings. These are conducted in partnership with MedCafe.ie. Recording of this Vhi 360 Hot Topics Webinar can be found on https://medcafe.ie/vhi_webinars.