Chronic Bowel Disorders
Coeliac disease and diverticular disease — dietary and pharmacological management
Chronic bowel disorders encompass a range of conditions requiring long-term management. This guide covers coeliac disease — an immune-mediated gluten enteropathy causing villous atrophy of the small bowel — and diverticular disease, in which colonic mucosal pouches may become inflamed or complicated. Both are common presentations in primary care and pharmacy practice, and careful evaluation guides appropriate dietary, pharmacological, and surgical management.
Coeliac Disease
Coeliac disease is an autoimmune condition triggered by dietary gluten (found in wheat, barley, and rye) in genetically susceptible individuals. It causes inflammation and villous atrophy of the small intestinal mucosa, leading to malabsorption. Symptoms include diarrhoea, steatorrhoea, bloating, weight loss, fatigue, iron and folate deficiency anaemia, oral ulcers, and dermatitis herpetiformis. Diagnosis requires tTG-IgA serology while the patient is eating gluten for at least six weeks, followed by endoscopy with duodenal biopsy showing villous atrophy (Marsh grading). Total IgA should be checked to exclude selective IgA deficiency, which can cause false-negative serology.
Coeliac Disease — Management and Monitoring
The cornerstone of treatment is a strict lifelong gluten-free diet, with dietitian referral at diagnosis. Most patients tolerate oats. ACBS-prescribable gluten-free products are available on the NHS. Nutritional deficiencies should be corrected — iron, folic acid, B12, vitamin D, and calcium supplementation as needed. A DXA scan at diagnosis assesses osteoporosis risk. Annual monitoring includes FBC, ferritin, B12, folate, vitamin D, and tTG-IgA to assess dietary adherence. Patients should receive pneumococcal and annual influenza vaccination due to functional hyposplenism.
Diverticular Disease and Diverticulitis
Diverticular disease involves the formation of colonic mucosal pouches (diverticula), most commonly in the sigmoid colon. Symptoms include left iliac fossa pain, altered bowel habit, and bloating. Acute diverticulitis presents with fever, localised peritonism, raised WCC and CRP, and nausea. CT abdomen with Hinchey classification grades severity. Mild diverticulitis is treated with oral co-amoxiclav for five days; moderate to severe cases require hospital admission for IV antibiotics. NSAIDs and opioids should be avoided. Long-term prevention centres on a high-fibre diet, adequate fluid intake, and regular physical activity. Elective sigmoid colectomy is considered for recurrent or complicated disease.