involuntary guarding

in·vol·un·tar·y guard·ing

abdominal muscle spasm, caused by retroperitoneal inflammation, which cannot be willfully suppressed.
References in periodicals archive ?
We report a 37 year old multi-parous lady, who in her third trimester of pregnancy, presented to the emergency room with acute diffuse abdominal pain and involuntary guarding.
Physical examination revealed a distended rigid abdomen, with involuntary guarding and generalized rebound tenderness.