Critical Red Flag: This is NOT Irritable Bowel Syndrome
Kelsey's presentation of diarrhea, cramping, AND bleeding requires immediate investigation for inflammatory bowel disease (IBD), colorectal cancer, or other serious pathology—bleeding is NOT a symptom of IBS and mandates urgent diagnostic workup before any IBS treatment is considered. 1
Immediate Diagnostic Workup Required
Essential Blood and Stool Tests
- Full blood count, C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), and coeliac serology must be performed immediately to exclude inflammatory conditions and coeliac disease 1
- Faecal calprotectin is mandatory in patients with diarrhea to exclude inflammatory bowel disease, as a negative test combined with normal CRP almost certainly rules out IBD 1, 2
- Ferritin should be checked given the presence of bleeding, as iron deficiency anemia may indicate significant blood loss 1
Endoscopic Evaluation
- Upper and lower GI endoscopy should be the initial diagnostic procedure for nearly all stable patients presenting with gastrointestinal bleeding 1
- Colonoscopy is indicated when there are alarm symptoms such as rectal bleeding, regardless of age, to exclude colorectal cancer, inflammatory bowel disease, or microscopic colitis 1
- Any colorectal stricture or abnormality must be assessed with endoscopic biopsies to ensure the absence of malignancy 1
Common Pitfall to Avoid
The single most dangerous error would be to diagnose IBS and provide symptomatic treatment without investigating the bleeding. Rectal bleeding is an alarm symptom that should always be treated with suspicion and warrants immediate investigation 2. IBS does not cause bleeding—if bleeding is present, another diagnosis must be sought 1.
If IBS is Confirmed After Excluding Serious Pathology
Only after organic disease has been excluded through appropriate testing should IBS treatment be considered:
First-Line Treatment Approach
- Regular exercise should be advised at the initial visit for all IBS patients 1, 3, 4
- Soluble fiber (ispaghula) starting at 3-4 g/day and gradually increasing is effective for global symptoms and abdominal pain, though insoluble fiber like wheat bran should be avoided as it may worsen symptoms 1, 3, 4
- Antispasmodics such as mebeverine or hyoscyamine are the initial drug choice for IBS pain and cramping, with mebeverine having direct inhibitory effects on intestinal smooth muscle 3, 5
For Diarrhea-Predominant Symptoms
- Loperamide may be effective for diarrhea and urgency but requires careful dose titration to avoid side effects including abdominal pain, bloating, and constipation 1, 4, 6
- Consider testing for bile acid malabsorption in patients with diarrhea, especially those with nocturnal diarrhea or prior cholecystectomy 1, 4
Second-Line Treatment if Symptoms Persist
- Tricyclic antidepressants (TCAs) such as amitriptyline starting at 10 mg once daily at bedtime and titrating to 30-50 mg are the most effective second-line treatment for global symptoms and abdominal pain after 3-6 weeks of failed first-line therapy 3, 4
- A low FODMAP diet can be used as second-line dietary therapy under dietitian supervision, implemented as a three-phase approach: restriction (4-8 weeks), reintroduction (6-10 weeks), and personalization (long-term) 1, 3, 4
Medical Certificate Justification
Work absence is justified during the acute diagnostic phase and initial treatment period, particularly given the severity of symptoms including bleeding that prevents normal function 1. The certificate should specify that the patient is undergoing investigation for gastrointestinal bleeding and associated symptoms, with fitness for work to be reassessed after diagnostic workup is complete.