Abdominal Distention Results From Caudo-ventral Redistribution of Contents

Background & Aims: Abdominal bloating is a frequent symptom in various categories of patients; however, its origin is unclear. Our aim was to establish the mechanisms of abdominal bloating. Methods: The study evaluated 56 patients whose predominant symptom was abdominal bloating. Of these, 47 (44 female and 3 male; aged 19-74 years) were diagnosed with functional intestinal disorder by Rome H criteria and 9 (7 female and 2 male; aged 18 - 64 years) were diagnosed with intestinal dysmotility by gastrointestinal manometry. Computed tomographic scans were obtained before (basal level) and during a severe bloating episode. Control scan were also obtained from 12 healthy subjects (11 female and 1 male; aged 19 - 62 years). Morphovolumetric differences between basal and severe bloating scans were measured using an original computer analysis program. Results: During severe bloating, patients with dysmotility exhibited anterior wall protrusion (23 +/- 4 mm; P < .001 vs basal) associated with a marked increase in total abdominal volume (1.4 +/- 0.3 L; P = .002 vs basal) and with cephalic displacement of the diaphragm. By contrast, in patients with functional intestinal disorder, total abdominal volume barely increased (0.3 +/- 0.1 L; P < .001 vs dysmotility); in these patients, abdominal distention (14 2 turn anterior wall protrusion; P < .001 vs basal) was related to diaphragmatic descent (-12 +/- 3 mm; R = - 0.62; P < .001). Conclusions: Abdominal distention might be caused by an increase in intra-abdominal volume or abdomino-phrenic displacement and ventro-caudal redistribution of contents.