Table 2.
Causes of irritable bowel syndrome-like symptoms in inflammatory bowel disease patients
| Disease | Diagnosis | Treatment |
| Small bowel CD | Computed tomography or magnetic resonance enterography | Drug escalation or surgery |
| Bile-acid malabsorption | 75SeHCAT, 48-hour fecal bile acids, trial with bile acid binders | Bile acid sequestrants |
| Exocrine pancreatic insufficiency | Fecal elastase1, trial with pancreatic enzymes | Pancreatic enzyme replacement |
| Carbohydrates intolerance | Hydrogen breath test | Dietary restriction |
| Small intestinal bacterial overgrowth | Lactulose or glucose breath tests: rise from baseline in H2 ≥ 20 ppm within 90 min or CH4 ≥ 10 ppm | H2: Rifaximin, doxycycline or amoxicillin CH4: Rifaximin and neomycin, or rifaximin and metronidazole, or amoxicillin-clavulanate or ciprofloxacin and metronidazole |
| Small intestinal fungal overgrowth | Quantitative culture of intestinal aspirate ≥ 103 CFU/mL | Anti-fungal therapy (e.g., fluconazole) |
| Dyssynergic defecation | Anorectal manometry with balloon expulsion test, defecography | Biofeedback behavior therapy |
| Ehlers-Danlos syndrome-hypermobility type | Beighton score ≥ 4[105] and arthralgia, erect barium testing for visceroptosis | Pelvic physiotherapy, promotility agents |
| Mast cell activation syndrome | Typical symptoms, elevated mast cell mediators (e.g., tryptase) and response to mast cell stabilizing agents | H1 blockers, H2 blockers, cromolyn sodium, referral to hematologist/allergist |
| Eosinophilic gastroenteritis | Eosinophilic infiltration on pathology | Anti-inflammatory agents |
| Intra-abdominal adhesions | Clinical history, previous history of adhesions | Consideration of surgical lysis of adhesions |
| Giardiasis | Detection of Giardia lamblia antigens in stool | Metronidazole or nitazoxanide |
| Celiac disease | IgA anti-tissue transglutaminase and serum total IgA, EGD with duodenal biopsies | Gluten-free diet |
1
False-positive results are observed in liquid stools. CD: Crohn’s disease; 75SeHCAT: Selenium-75-homocholic acid taurine scan; CFU: Colony-forming unit; H1: Histamine 1 receptor; H2: Histamine 2 receptor; EGD: Esophagogastroduodenoscopy.