Abdominal rigidity is stiffness of the muscles in the belly area, which can be felt when touched or pressed.

When there is a sore area in the abdomen, the pain becomes more intense as the hand presses against it and overcomes the muscular resistance.

A patient's fear or nervousness about being touched (palpated) in the abdominal area is referred to as voluntary rigidity. It usually occurs on both sides of the abdomen. Involuntary rigidity, usually caused by a physical condition, may affect one or both sides and may be associated with pain.

Nausea, vomiting, abdominal tenderness, swelling, and pain often accompany abdominal rigidity.

• Appendicitis
• Cholecystitis
• Gastrointestinal perforation
• Injury to the abdomen
• Peritonitis

Involuntary abdominal rigidity should always be evaluated by your health care provider.

All forms of involuntary rigidity and rebound tenderness (pain when the abdomen is gently pressed and then the pressure is suddenly released) require immediate medical attention, preferably in an emergency room. Surgery may be necessary.

You will probably be seen in an emergency room rather than at your doctor's office.

The health care provider perform a physical examination. The physical examination may include a pelvic (and possibly a rectal) examination.

The health care provider will ask questions about your symptoms, such as:

• When did it first start?
• What other symptoms occur at the same time? For example, do you have abdominal pain?

Diagnostic tests that may be performed include the following:

• Barium studies of the stomach and intestines (such as an upper GI series)
• Blood tests
• Colonoscopy
• Gastroscopy
• Peritoneal lavage
• Stool studies
• Urine tests
• X-ray of the abdomen
• X-ray of the chest

You will probably not be given any pain relievers until a diagnosis is made. Pain relievers can hide your symptoms.

Proctor DD. Approach to the patient with gastrointestinal disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 134.

Postier RG, Squires RA. Acute abdomen. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 45.