Visceral sensitivity in diagnostics and treatment of severe irritated bowel syndrome

Abstract

Background. Irritable bowel syndrome (IBS) is a biopsychosocial model based on the malfunction of "brain-intestinal linking".
 Aim. To improve diagnostics of the severe IBS accompanied with somatoform disorders by using balloon dilatation test (BDT) and optimize the therapy by using antidepressants from the serotonin and noradrenaline reuptake inhibitor type.
 Materials and methods. 61 patients with severe IBS and diarrhea were examined, among them 29 female with a median age of 31 years old (24; 36), and 31 male with a median age of 31 (24; 36) years old. All patients were randomized into two groups, group 1 consisted of 30 patients (15 female, 15 male), group 2 consisted of 31 patients (15 female, 16 male).
 The symptoms of all patients were assessed using the Visual Analogue Pain Scale (VAS Pain), visceral sensitivity index (VIS) was assessed according to the J. Labus questionnaire (2007) and visceral sensitivity threshold was assessed according to the BDT, the psycho-emotional state was assessed using the Beck scale of anxiety and depression and the Spielberger-Khanin scale. Both group patients underwent a comparative effectiveness evaluation between the therapy based on the use of Trimebutine at a dose of 600 mg per day and the SNRI-Duloxetine therapy at a dose of 60 mg per day for 8 weeks.
 Results. Patients from group with severe IBS and diarrhea who had undergone the antidepressant therapy showed the decrease of pain syndrome from 7 (5; 7) to 2.5 (2; 3) points according to VAS Pain; normalization of stool frequency from 7 (6; 9) to 2 (1; 2) times a day; normalization of stool consistency from 6 (6; 7) to 3 (3; 4) type; and decrease of VIS: first urge from 56 (34; 74) to 95 (80; 98) ml.; as well as the decrease of the depression level (Beck scale) from 26 (23; 32) to 11.5 (10; 13) points and anxiety according to Beck scale from 38 (31; 45) to 11 (10; 12), the decrease of personal anxiety level (Spielberger-Khanin scale) from 42.5 (35; 53) to 22 (20; 24) points, and the decrease of situational anxiety from 40 (37; 49) to 22 (21; 36) points. During the trimebutine therapy in group 1, the clinical symptoms of IBS have persisted. According to the BDT, the visceral sensitivity (HF) threshold remained at a low level. And the indicators of anxiety and depression remained at a high level according to the psychometric scales.
 Conclusion. The insufficient effect of the trimebutine therapy can be explained by the somatoform disorders persistence in patients from group 1. Meanwhile SNRI-duloxetine therapy in group 2 showed a clinical remission of IBS: such as a reliable relief from pain and diarrheal syndrome, as well as an increase in the HF threshold.
 Thus, Duloxetine is a promising treatment for severe IBS with somatoform disorders. BDT can be used as an objective criterion to diagnose and evaluate the effectiveness of therapy in patients with IBS.

Central Neuromodulators in Irritable Bowel Syndrome: Why, How, and When

“…Venlafaxine, dosed for depression at 75–225 mg, acts primarily as an SSRI at lower doses, but higher doses (>225 mg) are needed to achieve NA inhibition and be effective as a pain treatment ( 22 ). Duloxetine has a strong and similar affinity for the 5-HT transporter and NA, acting as a true SNRI even at lower doses; in a comparative study, duloxetine activity was evaluated in patients with IBS-D, and the results showed a clinical remission of pain and diarrhea, as well as an increase in the threshold of visceral sensitivity, using the balloon dilation test ( 7 , 22 ). Milnacipran is more potent in inhibiting the reuptake of NA compared with its ability to inhibit the reuptake of 5-HT.…”

“…Alternatively, a secondary amine having less anticholinergic effect or duloxetine may be prescribed ( 6 , 22 ). In a randomized study conducted with 61 patients with IBS-D, SNRI-duloxetine therapy showed a significant clinical remission of pain and diarrhea ( 7 ). In patients with diarrhea where the anxiety component is predominant over pain, paroxetine could be chosen since it has greater anticholinergic effects than the other SSRIs ( 6 , 22 , 51 ).…”

“…Since IBS and other DGBI are caused by dysregulation of the BGA (see below), neuromodulators serve to normalize their action. Specifically, they have effects to (i) treat psychiatric comorbidity, (ii) modify gut motility, (iii) improve central downregulation of visceral signals, and (iv) enhance neurogenesis (6)(7)(8).…”

“…However, the value of neuromodulator treatment in IBS goes beyond its association with neuropsychiatric disorders ( 6 ). Neuromodulators act directly in regulating different pathophysiological mechanisms involved with visceral or central hypersensitivity, alterations of intestinal transit, or neurogenic effects, all of which are responsible for the clinical manifestations of IBS ( 6 , 7 ). This approach allows us to choose therapeutic alternatives based on symptom intensity and the nature of the symptoms (e.g., pain, diarrhea, constipation) treated ( 6 ).…”