Patterns:

• Because both the smooth and skeletal muscles are involved in DM1, dysfunction along the entire gastrointestinal (GI) tract is common in this disorder. Children with CDM may have profound oral facial weakness that prevents oral intake and requires a gastrostomy tube. This will improve with age, though not completely.

Symptoms:

• Gastrointestinal issues.

• Constipation, diarrhea, fecal incontinence, which can result in fecal impaction and megacolon.

• Gastrointestinal dysmotility that frequently results in pseudo-obstruction and can lead to aspiration.

• Aspiration, abdominal pain and bloating.

• While children with childhood-onset DM1 do not have neonatal feeding problems, they may have any of the other symptoms. Children may have urinary incontinence and difficulty toilet training. This may resolve, or partially resolve, with age.

Treatment:

• Feeding support should be managed by nasogastric tube initially, as many children with CDM will improve in feeding function over time. Placement of a gastrostomy-tube for longer term feeding is warranted for those who do not show improvement by one month of age, corrected for prematurity if needed.

• Fiber supplementation (more than 8 grams daily) for children with constipation or diarrhea.

• Gentle laxatives for constipation:

  • First-line therapy recommendations: polyethylene glycol (Miralax), senna (Ex-Lax, Senokot), docusate (Colace) or lactulose (Cholac).

  • Second-line therapy recommendations: bisacodyl (Dulcolax, Correctol), lubiprostone (Amitiza) or linaclotide (Linzess).

  • Metoclopramide (Reglan) to reduce the symptoms of gastroparesis, pseudo-obstruction and gastric reflux. Long-term use is not recommended because this drug can cause tardive dyskinesia.

  • Antibiotics to reduce diarrhea if bacterial overgrowth is found on breath testing.

  • Referral to a gastrointestinal specialist for anal manometry should be considered if a patient does not respond to the first- or second-line recommendations above.

  • Oils should be avoided.

• Mexiletine may be considered for refractory diarrhea or constipation.

• Refer to speech therapy for children with a feeding tube. Children should be periodically re-assessed for improving dysphagia.

• Children with CDM often benefit from dysphagia therapy. With aggressive dysphagia therapy, children with CDM often are able to PO feed within the first year of life.