Parkinson's Toolkit

Common Causes

• Impairment in gut motility
• Dysfunction in muscles of the pelvic floor that promote defecation
• Medications such as anticholinergics (trihexyphenidyl, benztropine, oxybutynin, amantadine)

Diagnosis

• History;
• Bowel movement diaries
• Bristol Stool Form Scale–Types 1 and 2 indicate constipation

Barriers to Diagnosis

• Failure to disclose. (Ask direct question: “Do you have a BM every day?”

Treatment Options

• Increased water intake and fiber in the diet are the first steps.
• Exercise may also improve bowel movement frequency.
• Bulk forming agents such a psyllium can be added to the diet.
• Laxatives such as polyethylene glycol 3350 should be added if these measures fail.
• If required, introduce relatively safe antiemetics including domperidone (outside the US), trimethobenzamide, and ondansetron.

Important Caveats to Therapy

• Occasionally, moderate to advanced PD patients can become so constipated that they develop an impaction with intestinal obstruction. This requires immediate attention and evaluation/treatment, perhaps requiring hospitalization.
• It is important to avoid GI drugs (such as prochlorperazine, metoclopramide, and promethazine) that may worsen parkinsonism.
• Patients often do no adhere to treatment plans due to fear of “dependence” on bowel routine and lack of understanding the impact of severe constipation (can cause bowel obstruction).