Colonoscopy-related Pain Predicts the Treatment Response of Amitriptyline in Patients With Irritable Bowel Syndrome

Study Overview
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Brief Summary
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Irritable bowel syndrome (IBS) is a functional bowel disorder with recurrent abdominal pain and disordered defecation and is one of the most common gastrointestinal problems. In practice, IBS was frequently diagnosed as an exclusion diagnosis for patients with recurrent abdominal pain without an organic cause. Visceral hypersensitivity is the major contributing factor of abdominal pain in IBS. Accordingly, tricyclic antidepressants (TCAs) are widely used for IBS, especially if abdominal pain is a prominent symptom. Indeed, meta-analysis also exhibits the clinically significant efficacy of low dose TCAs in IBS. Nevertheless, over 40% of IBS patients receiving TCAs had no improvement in symptoms after treatment. Theoretically, if TCAs are used for IBS patients with hypersensitivity, its efficacy could be increased. Although rectal distension test might be used to identify hypersensitive patients with IBS, it has been used only for clinical research because it is painful for the patient. On the contrary, colonoscopy is frequently performed in IBS patients to rule out organic disease and for the purpose of colorectal cancer screening. In a study by Kim and colleagues, IBS patients reported higher pain score after colonoscopy than non-IBS patients. This has prompted the hypothesis that pain scoring during/after colonoscopy could also segregate IBS patients with visceral hypersensitivity showing better treatment response of TCA than those without. The aims of the present study were to evaluate the colonoscopy-related pain perception and the treatment response of amitriptyline in IBS patients and to investigate the predictive values of the colonoscopy-related pain scale in identifying IBS patients with a response to amitriptyline treatment.

Official Title
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Colonoscopy-related Pain Predicts the Treatment Response of Amitriptyline in Patients With Irritable Bowel Syndrome

Conditions
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Irritable Bowel Syndrome

Intervention / Treatment
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* Drug: Amitriptyline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with IBS according to the Rome III criteria Exclusion Criteria: Inflammatory bowel disease or malignancy on colonoscopy. Previous abdominal surgery other than appendectomy or cesarean delivery, Major psychiatric disorders or Beck Depression Inventory-II score of ≥19 Significant cardiopulmonary diseases or any malignancies Taking pain modulators including selective serotonin reuptake inhibitors (SSRI) or tricyclic antidepressants Polypectomy during colonoscopy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Amitriptyline|This was a prospective, observational study conducted at Samsung Medical Center, Seoul, Korea. Enrolled IBS patients underwent colonoscopy and colonoscopy-related pain score was evaluated. After colonoscopy, all patients received 5 mg amitriptyline once daily at bedtime for the first week and 10 mg for the subsequent 3 weeks. After the intervention period of 4 weeks, the treatment response was determined.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| treatment response of abdominal pain/discomfort | The primary outcome was the treatment response of abdominal pain/discomfort. The investigators defined a response when a patient experienced a fall of 30% in abdominal symptom compared to baseline. | After the intervention period of 4 weeks, the treatment response was determined. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| treatment responses of urgency of defecation | The secondary outcomes were the treatment responses of urgency of defecation, bloating, and overall IBS symptoms scores. | After the intervention period of 4 weeks, the treatment response was determined. | 
| treatment responses of bloating |  | After the intervention period of 4 weeks, the treatment response was determined. | 
| treatment responses of overall IBS symptoms scores |  | After the intervention period of 4 weeks, the treatment response was determined. |