Symptoms:

• Brownish or bluish-gray pigmented spots on the lips, gums, inner lining of the mouth, and skin
• Clubbed fingers or toes
• Cramping pain in the belly area
• Dark freckles on and around the lips of a newborn
• Blood in the stool that can be seen with the naked eye (occasionally)
• Vomiting

Signs and tests:

The polyps develop mainly in the small intestine, but also in the colon. A colonoscopy will show colon polyps. The small intestine is evaluated with either a barium x-ray (small bowel series) or a small camera that is swallowed and then take multiple pictures as it travels through the small bowel (capsule endoscopy).

Additional exams may show:

• Intussusception (part of the intestine folded in on itself)
• Noncancerous tumors in the ear (exostoses)

Laboratory tests may include:

• Complete blood count -- may reveal anemia
• Genetic testing
• Stool guaiac
• Total iron-binding capacity (TIBC)