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 II 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 scans were also obtained from 12 healthy subjects (11 female and 1 male; aged 19-62 years). Morpho-volumetric 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 mm 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.