Constipation

I.                    Definition: less than 3 stools per week.

II.                 Pathogenesis: stool volume, colonic motility, patency of colon’s lumen

a.       Stool volume

                                                               i.      Decreased fluid and fiber intake

b.      Colonic motility

                                                               i.      Medical conditions: hypothyroidism, hypercalcemia, kypokalemia, scleroderma, diabetes, multiple sclerosis, Parkinson disease, paraplegia

                                                             ii.      Medications: calcium channel blockers (verpamil), narcotics, anticholinergics

                                                            iii.      Other: IBS (frequent looser stools), sedentary lifestyle or bed rest (after surgery), Hirshprung disease.

c.       Patency of colon’s lumen

                                                               i.      Cancer, strictures, external compression

d.      Anorectal disorders: fissures, hemorrhoids. Cause pain so patient avoids defecation.

III.               Treatment: increasing fluid and fiber and medications.

a.       Bulking agents

                                                               i.      Psyllium (Metamucil)

                                                             ii.      Methylcellulose (Citrucel)

                                                            iii.      Calcium polycarbophil (FiberCon)

b.      Softeners

                                                               i.      Docusate sodium (Colace)

c.       Stimulants

                                                               i.      Bisacodyl (Dulcolax)

                                                             ii.      Senna (Senokot)

                                                            iii.      Casanthranol (Peri-Colace)

d.      Osmotics

                                                               i.      Lactulose (Cephulac)

                                                             ii.      Magnesium (milk of magnesia, magnesium citrate)

                                                            iii.      Sorbitol