A 71-year-old woman comes to the physician for constipation. She has had 1-2 bowel movements a week associated with straining and the sensation of incomplete evacuation for the past 5 years. She has no rectal bleeding, abdominal pain, weight loss, pain with defecation, change in stool caliber, or diarrhea. The patient has increased her exercise and fluid intake without improvement in symptoms. She had a colonoscopy 3 years ago in which only 1 small hyperplastic polyp was found. Her past medical history includes hypertension, for which she takes chlorthalidone.
Vital signs are normal and her body mass index is 29 kg/m². Physical examination and rectal examination, which shows normal sphincter tone and no palpable masses, are unremarkable.
Laboratory tests, including electrolytes, renal function, and thyroid studies, are within normal limits. A radio marker study is performed and demonstrates delayed motility in the proximal colon.
Which of the following is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

11ec193a_9817_8b02_853d_d30bc013b58f_MD0002_00 This patient's history is most consistent with slow transit constipation, confirmed by a radio marker study showing prolonged transit time through the colon. Chronic constipation is a common disorder in adults and increases in prevalence with age. Treatment includes the discontinuation of common offending medications (calcium channel blockers, anticholinergics, opioids, nonsteroidal anti-inflammatory drugs), increasing dietary fiber/fluids, and engaging in daily exercise. If nonpharmacologic therapies fail, addition of a bulking agent, such as methylcellulose or psyllium, is recommended. These agents are effective in increasing the frequency and softening the consistency of stool with very few side effects. Additional diagnostic evaluations, including colonoscopy (Choice D), should be considered for those with the following: Alarm features (gross or occult bleeding, acute onset of constipation or mechanical obstruction, unexplained weight loss, change in caliber of stool)Symptoms refractory to medical managementFeatures of pelvic floor dysfunction (ie, inability to expel stool due to lack of relaxation of pelvic floor muscles) Alarm features (gross or occult bleeding, acute onset of constipation or mechanical obstruction, unexplained weight loss, change in caliber of stool) Symptoms refractory to medical management Features of pelvic floor dysfunction (ie, inability to expel stool due to lack of relaxation of pelvic floor muscles) (Choice B) Colonic secretagogues, such as lubiprostone and linaclotide, act by stimulating intestinal fluid secretion and decreasing colonic transit times. These agents are more commonly used in irritable bowel syndrome constipation-type (IBS-c) and are used in severe chronic constipation only after failure of other therapies. In addition to constipation, symptoms suggesting IBS-c include recurrent abdominal pain, distension, intermittent loose stools, and passage of mucus. (Choice C) Osmotic laxatives (polyethylene glycol) are also effective in slow transit constipation, but excessive use of these agents may result in volume overload and electrolyte abnormalities (hypokalemia). The current guidelines therefore recommend a trial of supplemental fiber as first-line therapy. (Choice E) Enemas are recommended for those at risk of fecal impaction from severe, refractory constipation. Sodium phosphate enemas are generally avoided in older adults due to potential complications including volume depletion, hypotension, and acute phosphate nephropathy. Tap water would be preferred if it becomes necessary to use an enema in this patient. Educational objective: In the absence of alarm features, chronic slow-transit constipation can be treated with dietary fiber and lifestyle changes. If pharmacologic therapy is indicated, an initial trial of bulk-forming laxatives such as methylcellulose or psyllium is preferred. __________ References: Evaluation of constipation. (http://www.ncbi.nlm.nih.gov/pubmed/23449159) Chronic constipation in the elderly. (http://www.ncbi.nlm.nih.gov/pubmed/21989145)

A 71-Year-Old Woman Comes to the Physician for Constipation