Abdominal Palpation Does Not Modify the Number of Bowel Sounds in Healthy Volunteers and Gastrointestinal Outpatients.

Background: The effect of abdominal palpation on bowel sounds is controversial. The authors developed an auscultation apparatus to count bowel sounds and determined whether abdominal palpation modifies the number of bowel sounds in healthy volunteers and gastrointestinal outpatients.

Methods: Four medical students developed an auscultation apparatus by attaching a Littmann stethoscope to an electret condenser microphone. The students examined 20 healthy volunteers and 20 gastrointestinal outpatients between March and June 2018. Abdominal auscultation lasting 4 minutes (1-minute each quadrant) was performed before and after abdominal palpation with registration of sound tracings. The software Audacity was used to count the bowel sounds. The effect of palpation on bowel sounds was analyzed using Generalized Estimating Equations.

Results: The volunteers were predominantly young (mean ± SD, 21 ± 2 years) and men (70%), whereas the outpatients were older (60 ± 11 years) and women (80%). The apparatus was able to generate sound tracings with good quality from all participants. In the comparison before/after palpation, the number of bowel sounds did not differ either in volunteers (mean ± SD, 12.6 ± 4.7 and 11.6 ± 3.5; P = 0.482) or in patients (15.6 ± 7.5 and 15.8 ± 7.9; P = 0.714). In the analysis of all participants, the difference before-after palpation was not statistically significant (mean ± SD, 14.1 ± 6.3 and 13.7 ± 6.4, respectively; P = 0.550; mean difference = 0.4; 95% CI -1.2 to 2.0) and did not depend on the group studied.

Conclusions: Using an apparatus devised by medical students, the authors found that abdominal palpation did not modify the number of bowel sounds in healthy volunteers and gastrointestinal outpatients.