What are the treatment options for gastrointestinal (GI) illnesses?

Treatment Options for Gastrointestinal Illnesses

Treatment of GI illnesses requires a systematic diagnostic approach to distinguish inflammatory from functional disease, followed by targeted pharmacologic, dietary, and behavioral interventions based on the underlying pathophysiology.

Diagnostic Framework Before Treatment

A stepwise approach must rule out ongoing inflammatory activity before attributing symptoms to functional disease. 1, 2, 3

• Measure fecal calprotectin as the only validated biomarker to distinguish organic from functional disease 1, 3
• Perform colonoscopy with biopsies to evaluate for IBD, microscopic colitis, or other mucosal pathology when calprotectin is elevated 1, 3
• Obtain cross-sectional imaging (CT or MRI enterography) for patients with obstructive symptoms including abdominal distention, pain, nausea, vomiting, or constipation to assess for structural complications 1, 3

Alternative mechanisms beyond inflammation must be systematically evaluated based on symptom patterns: 1, 3

• Perform glucose or lactulose hydrogen breath testing for small intestinal bacterial overgrowth (SIBO), particularly with bloating and postprandial symptoms 3
• Consider SeHCAT scan or empiric trial of bile acid sequestrants (cholestyramine 4g with meals) for postprandial diarrhea 3, 4
• Test for lactose and fructose intolerance with breath testing, as carbohydrate malabsorption is more frequent in IBD and can persist in remission 3
• Check tissue transglutaminase IgA and total IgA to exclude celiac disease 3

Treatment of Inflammatory Bowel Disease

First-Line Therapy for Mild-Moderate Disease

Aminosalicylates (5-ASA compounds) are effective for mild to moderate ulcerative colitis but have limited effectiveness in Crohn's disease. 2

• Initiate mesalazine ≥2g/day for mild-moderate ulcerative colitis 3
• Use 5 mg/kg infliximab at 0,2, and 6 weeks, then every 8 weeks for moderate-severe Crohn's disease or ulcerative colitis 2, 5
• Some adult patients who initially respond may benefit from increasing the dose to 10 mg/kg if they lose their response 2

Second-Line Therapy for Steroid-Dependent Disease

Immunomodulators are recommended for chronic active steroid-dependent disease with mandatory monitoring. 2

• Prescribe azathioprine 1.5-2.5 mg/kg/day or mercaptopurine 0.75-1.5 mg/kg/day for moderate-severe or steroid-dependent disease 3
• Monitor full blood count regularly to detect neutropenia 2

Critical pitfall: The risk of hepatosplenic T-cell lymphoma (HSTCL) is highest in adolescent or young adult males with Crohn's disease or ulcerative colitis receiving azathioprine or 6-mercaptopurine concomitantly with TNF-blockers. 5

Biologic Therapy

Biologic therapy should be considered for refractory disease after discussion of risks, benefits, and surgical options. 3

• Infliximab carries increased risk of serious infections including tuberculosis, bacterial sepsis, and invasive fungal infections 5
• Perform testing for latent TB before initiating infliximab; if positive, start TB treatment prior to starting biologic therapy 5
• Monitor all patients for active TB during treatment, even if initial latent TB test is negative 5
• Discontinue infliximab if a patient develops a serious infection 5

Treatment of Functional GI Symptoms

Symptom-Specific Pharmacologic Management

For chronic diarrhea in quiescent IBD, hypomotility agents or bile-acid sequestrants are first-line. 1, 2

• Use loperamide for mild diarrhea control 4
• Prescribe bile acid sequestrants for suspected bile acid malabsorption 4

For chronic constipation, osmotic and stimulant laxatives should be offered. 1, 2

For functional pain, use antispasmodics, neuropathic-directed agents, or antidepressants while avoiding opiates. 1, 2

• Tricyclic antidepressants are strongly recommended as effective second-line therapy for global symptoms and abdominal pain 4
• Start at low dose and titrate gradually 4
• Selective serotonin reuptake inhibitors may be effective for global symptoms, particularly with comorbid anxiety or depression 4

For severe IBS-D symptoms, 5-HT3 receptor antagonists are the most efficacious drug class. 4

• Eluxadoline is a mixed opioid receptor drug that slows intestinal transit and reduces visceral hypersensitivity 4
• Critical contraindication: Eluxadoline is contraindicated in patients with prior sphincter of Oddi problems 4

Dietary Interventions

A low FODMAP diet may be offered for functional GI symptoms with careful attention to nutritional adequacy. 1, 2, 3

• Start soluble fiber at low dose and gradually increase to avoid bloating 4
• Reduce caffeine and alcohol intake 4
• Ensure adequate hydration 4

Psychological Therapies

Psychological therapies including cognitive behavioral therapy, hypnotherapy, and mindfulness therapy should be considered for IBD patients with functional symptoms. 1, 2

• Integrate psychological therapies when symptoms are refractory to drug treatment for 12 months 4
• Solution-focused therapy for fatigue in quiescent IBD has shown reduction in fatigue for up to 3 months 2

The brain-gut axis education is essential: The brain and gut communicate continually through nerves and chemical signals, and the brain can be trained through specialized psychological treatment to reduce intestinal disturbance regardless of whether it is actively contributing to symptoms. 1

Adjunctive Therapies

Probiotics may be considered for treatment of functional symptoms in IBD. 1, 2

• Trial probiotics for up to 12 weeks, discontinuing if no improvement occurs 4

Physical exercise should be encouraged in IBD patients with functional GI symptoms. 1, 2, 4

Pelvic floor therapy should be offered to IBD patients with evidence of an underlying defecatory disorder. 1, 2

Fecal microbiota transplant should not be offered for treatment of functional GI symptoms in IBD until further evidence is available. 1, 2

Complementary and alternative therapies should not be routinely offered for functional symptoms in IBD until further evidence is available. 1, 2

Treatment of Acute Gastroenteritis

Oral rehydration solution (ORS) is as effective as intravenous therapy for mild-to-moderate dehydration and should be first-line treatment. 6, 7, 8, 9

• Use ORS early with maintenance or timely resumption of regular feeding 6
• Reduced osmolarity ORS formulations have enhanced efficacy 6
• For every 25 children treated with ORT, one will fail and require intravenous therapy 9

Antiemetics allow for improved tolerance of oral rehydration solution and can decrease the need for intravenous fluids and hospitalization. 7, 8

• Ondansetron enhances compliance with oral rehydration therapy and decreases hospitalization rates 8

Surgical Considerations

Surgery is recommended for ulcerative colitis not responding to intensive medical therapy, with decisions made jointly by gastroenterologist and colorectal surgeon in consultation with the patient. 2

For Crohn's disease, surgery should only be considered when symptomatic, as it is potentially panenteric and usually recurs following surgery. 2

Infection Prevention in Immunosuppressed Patients

IBD patients on immunomodulatory treatment require specific preventive measures: 1

• Ensure influenza vaccine for all non-vaccinated IBD patients 1
• Ensure pneumococcal vaccination for all non-vaccinated IBD patients 1
• Practice hand hygiene using soap and water for 20-40 seconds 1
• Avoid contact with infected people and crowded places 1
• Discourage traveling during periods of high infection risk 1