The American Academy of Physical Medicine and Rehabilitation (AAPM&R): Physical medicine and Rehabilitation (PM&R) Knowledge Journal:

True visceral pain is a physiologically and clinically separate entity from somatic pain.  Visceral pain responses are provoked by ischemia, inflammation, and distention. Visceral pain is poorly defined and diffuses and commonly described as deep, gnawing, twisting, aching, colicky, or dull. It is usually associated with autonomic features (e.g. sweating, nausea and vomiting) and highly emotional (e.g. anxious, feeling of impending doom).

Clinical Variants of Abdominal and Pelvic Visceral Pain

1. True Visceral Pain
• Nociception arises from pain fibers in deep-lying abdominal or pelvic organs
• (+) tissue injury
2. Visceral Hyperalgesia
• Slow, poorly localized i.e. colic

3. Viscero-Viscero Hyperalgesia
• Sensory interaction between two different organs that share the same sensory pathway
4. Viscero-Somatic Pain
• Pain experienced in a somatic portion of the body secondary to organ irritation due to shared somatic and visceral innervation (e.g., Left shoulder pain secondary to a ruptured spleen)

History

1. The onset is often insidious
2. Pain is poorly localized. Exceptions include biliary, pancreatic, renal, appendix
3. True visceral pain is dull/colicky pain, but depending on the etiology the pain can transform to sharp

Current treatment guidelines

Generally accepted treatment for visceral pain includes treating the underlying pathology. This pathology, in many cases of visceral pain, is either caused by infection, ischemia, inflammation or malignancy of the involved organ system. Treatment is directed at the pathology. Rehabilitation- involves early mobilization, transfers, bed mobility, wound care.

At different disease stages

New onset/acute: It is essential to confirm the accurate diagnosis, as visceral pain is generally poorly localized and can mimic other pathologies within the abdomen and pelvis. Once confirmed, visceral and pelvic pain may improve or resolve with appropriate treatment.

A surgical evaluation may be necessary for certain diagnoses [e.g. bowel obstruction, cholecystitis, appendicitis (both visceral and somatic), etc.].

Intravenous analgesia (inpatient only, typically post-operatively):

• Ibuprofen
• Acetaminophen
• Opiates
• Ketamine

Oral analgesia:

• Nonsteroidal anti-inflammatories drugs (NSAIDs)
• Acetaminophen/Paracetamol
• Antiseizure medications
• Nonselective serotonin reuptake inhibitors
• Antispasmodics
• Opioids as a last line therapy

Topical:

• Lidocaine
• Prilocaine/lidocaine
• Capsaicin

Percutaneous Sympathetic Blocks