Irritability and abdominal pain in the neonate: Diagnosing and treating visceral hyperalgesia (203)

Visceral hyperalgesia is an underlying source of neuropathic pain that often presents as irritability, feeding intolerance, and hypertonicity. It is defined as an increased sensitivity to pain in the internal organs of the body, most commonly in the gastrointestinal (GI) tract. As a result, a normal non-painful stimulus, such as distension of the stomach or intestine that naturally occurs with feedings or gas, can activate a pain response. There is no specific diagnostic criteria for visceral hyperalgesia, so it is usually diagnosed by excluding other etiologies. Treatment of visceral hyperalgesia is usually aimed at lessening GI distension or facilitating the return of normal nerve sensitivities. Diet changes such as lower feeding volumes and rate of feeds are first steps in reducing GI distension. Infants can be changed to continuous feeds or vented between feeds as a way to reduce pressure in the stomach. In extreme cases, infants may need to be made NPO and given parenteral nutrition while treatment options are being considered. Antispasmodics have been shown to improve symptoms of visceral hyperalgesia by relaxing the smooth muscles in the GI tract. Probiotics have been found to potentially improve bloating by altering the gut microbiome, thus decreasing GI distension and pain. Gabapentin or Lyrica are the most common treatments for neuropathic pain and have been shown to be effective in improving nerve hypersensitivity. Tricyclic antidepressants, anticholinergics, and anti-nausea medications have also been used and shown improvement in symptoms.