If the patient seems to be overreacting to palpation, or if guarding does not seem genuine, ask the patient questions and have him or her answer during palpation. It's difficult to talk and voluntarily guard at the same time. If the pain is real, the patient will stop talking during guarding. Avoid gross tests for rebound tenderness, which require pressure and quick release. They are not precise and are very uncomfortable.
Light percussion is just as informative.
Any pain elicited in the obese patient is significant. The panniculus acts as a damper to pressure. Note pulse rate and rhythm, blood pressure, temperature, respiratory rate, and the characteristics of the respiratory cycle. Hypotension can result from gastrointestinal bleeding, dehydration, vagal stimulation, etc. Note any abdominal asymmetry, distension, bulges, scars, or splinting of the chest or abdomen during respiration.