Rectal Exam Needed to Determine Cause of Constipation

Laird Harrison

May 18, 2019

SAN DIEGO — By skipping rectal examinations as part of their workup, physicians may be missing the cause of constipation for some, a new study suggests.

Constipation is one of the most common reasons that patients present to a gastroenterologist or primary care clinic, and digital rectal exams are recommended for constipation workups by the American Gastroenterological Association (Gastroenterology. 2013;144:211–217).

Digital rectal examinations can determine whether the patient has dyssynergic defecation, which causes between 20% and 80% of chronic constipation, Shalaka Akolkar, DO, told Medscape Medical News.

"It can curb healthcare costs and improve patients' lives because they don't have to go through multiple imaging and testing before having a diagnosis," she explained.

But in a retrospective review of constipation workups at two community hospitals, Akolkar and her colleagues found that only 7% included digital rectal exams. Akolkar, from Ascension Providence Hospital in Southfield, Michigan, presented the finding here at Digestive Disease Week (DDW).

The researchers identified 184 patients who made 345 office visits, receiving a total of 24 digital rectal exams. They couldn't find comments in any of the records on maneuvers testing for dyssynergia.

On average, the digital rectal exam was not performed until the third visit. Before any digital rectal exam, 50% of the patients underwent imaging. Thirty-two percent had x-rays, 18% had computed tomography (CT) scans, and 36% had colonoscopies. The patients received an average of 1.8 laxatives before getting a digital rectal exam.

It's easier to order an x-ray.

Both physicians and patients may feel some discomfort with digital rectal examinations, said Akolkar. Some male physicians won't perform one on a female patient unless a chaperone is present, making it more difficult to arrange, she said. "I think a big factor is time," she said. "It's easier to order an x-ray."

But she speculated that many physicians are not performing the procedure because they are not aware of its importance in a constipation workup. "Before I did this study, I was unaware of it," said Akolkar, who is a resident.

Patients who made more office visits were more likely to get digital rectal exams (odds ratio [OR], 1.4) and so were those who had more tests overall (OR, 3.9).

All of this testing and laxative prescribing could be avoided for many patients whose actual problem is dyssynergic defecation, said Akolkar. "They're contracting their sphincter when they should be relaxing it. You can train the patients to realize that they're doing this and help the constipation to kind of relieve itself." Biofeedback methods can be used for this kind of training, she said.

To test if a patient suffers from this problem, physicians should ask the patient to contract and bear down, then relax, as if having a bowl movement, she explained. The physician should feel more contraction higher up and less lower down; if the sphincter is contracted everywhere, that is a sign of dyssynergic defecation, she said. "The anal vault should not be tight around the finger."

Her poster presentation raised the awareness of at least one clinician. "I see a lot of patients with constipation," said Richard Woller, PA, from Bay State Medical Center in Springfield, Massachusetts. "And a digital rectal exam in general is not the first thing I do."

After talking to Akolkar, he planned to try the exam to see if he found any cases of dyssynergic defecation.

"Most of the time I ask them about diet and lifestyle," he said. "They change them and when they come back they are doing fine."

Woller has done a lot of digital rectal exams, however, especially when patients are bleeding. Often patients express discomfort with having a digital rectal exam, and some have even refused. But he is often able to gain their cooperation by carefully explaining each step of the procedure, both before and during it, he said.

Akolkar and Woller report no relevant financial relationships.

Digestive Disease Week (DDW) 2019: Abstract Sa1086. Presented May 18, 2019.

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