Etiologies of Constipation

Primary etiologies: slow transit vs. pelvic floor dyssynergia

Secondary etiologies (4 Ms; JAMA 2016:315:185)

Mech obstruction:

malignancy, compression, rectocele, strictures

Meds:

opioids, TCAs, anticholinergics, CCB, NSAIDs, diuretics, Ca2+, Fe, low fiber diet

Metabolic/endo:

DM, hypothyroid, uremia, preg, panhypopit, porphyria, ↑ Ca, ↓ K, ↓ Mg

Myopathy/Neuro:

Parkinson’s, Hirschsprung’s, amyloid, MS, spinal injury, dysautonomia