Chronic Constipation

Drugs: opiates, nonsteroidal anti-inflammatory, anticholinergic, antidepressant, antihistamine, anti-Parkinsonian, iron, calcium

Neurogenic: autonomic neuropathy, Parkinson’s disease, multiple sclerosis, CNS and spinal cord lesions, pseudo-obstruction, diabetes mellitus, pelvic nerve damage

Myogenic: connective tissue disorders, amyloidosis, diabetes mellitus, dermatomyositis, pseudo-obstruction

Lifestyle: low fiber, very high fiber, dehydration, institutional living, low physical activity

Miscellaneous: pregnancy, anal and colon cancer, psychological disorders, intestinal radiation, long-distance travel

Normal transit includes chronic functional (idiopathic) constipation (see Table 15.2) and IBS-C (see Table 15.3; also see Chap. 16). Patients experience constipation without abnormalities in diagnostic tests.

Table 15.2

Diagnostic criteria for chronic functional idiopathic constipation

Criteria to be fulfilled for the last 3 months and symptom onset at least 6 months prior to diagnosisa

1. Must include two or more of the following:

(a) Straining during 25 % of defecations

(b) Lumpy or hard stools in at least 25 % of defecations

(d) Sensation of outlet obstruction for at least 25 % of defecations

(e) Manual maneuvers (digital extraction, perineal support) to facilitate at least 25 % of evacuations

(f) Fewer than 3 defecations per week

2. Looser stools are rarely present without the use of laxatives

3. There are insufficient criteria for IBS

Adapted from Longstreth GF, Thompson WG, Chey WD, et al. Functional bowel disorders. Gastroenterology. 2006;130:1480–91

^aCriterion fulfilled for the last 3 months with symptom onset at least 6 months to diagnosis

Table 15.3

Rome III irritable bowel syndrome, constipation predominant

Recurrent abdominal pain or discomfort (uncomfortable sensation not described as pain) at least 3 days/month in the last 3 months associated with two or more of the following:a

1. Improvement with defecation

2. Onset associated with a change infrequency of stool

3. Onset associated with a change in form (appearance) of stool

4. <25 % of bowel movements were loose stools

Adapted from Longstreth GF, Thompson WG, Chey WD, et al. Functional bowel disorders. Gastroenterology. 2006;130:1480–91

^aCriterion fulfilled for the last 3 months with symptom onset at least 6 months to diagnosis

Outlet dysfunction (defecation disorders, pelvic floor dysfunction) can be due to a number of conditions, including dyssynergia, excessive or inadequate perineal descent, rectal prolapse, anal stricture or fissure, hyposensitivity, rectocele or, rarely, intussusception or enterocele.

Slow-transit constipation is associated with a reduction in both the number and strength of high-amplitude propagating contractions (HAPC), which normally occur upon awakening and after meals. The pathogenesis may relate to a reduced number of neurons within the myenteric plexus and/or interstitial cells of Cajal and increased intestinal collagen deposition.

Diagnosis and Evaluation

The diagnosis of constipation tends to be subjective for patients being based on social and cultural norms. There is often a lack of agreement between “physicians” and patients’ perceptions of constipation, with physicians perceiving constipation as fewer than three stools per week and patients more concerned with stool consistency, sense of complete evacuation, and ease and of passage. Many people with fewer than three stools per week do not consider themselves constipated, while others ardently strive for “a healthful” one movement daily. This perception of constipation has been linked to the expenditure of millions of healthcare dollars.

The evaluation of constipation needs to be individualized to a patient’s medical needs and symptoms. Not all patients require the same diagnostic approach. The first step in the evaluation of constipation is a detailed history (see Table 15.4) and physical examination. A medication history is important as many drugs and supplements can cause constipation (see Table 15.1). The presence of alarm symptoms (see Table 15.5) or an abdominal mass requires additional evaluation which may include laboratory tests, a colonoscopy or a CT scan of the abdomen and pelvis. Laboratory evaluation including chemistries, complete blood count, and thyroid-stimulating hormone are commonly performed. The physical examination requires careful visual examination of the perineum to assess symmetry and inspection for a fistula, fissure or hemorrhoid, and the degree of perineal descent and prolapse with bearing down. The digital examination determines the presence of anal pain, sphincter length, symmetry, and tone (scale 0–5, least to greatest) at rest/with squeeze/with bearing down and may detect a band-like contraction of the puborectalis muscle anteriorly with bearing down, if dyssynergia is present. When asked to simulate defecation, abdominal muscles should contract together with relaxation of the anal sphincter complex. The absence of a failure to contract the abdominal muscles, absence of perineal descent, and/or a failure to relax or a paradoxical contraction of the anal sphincter is predictive of a diagnosis of dyssynergia.

Table 15.4

Key bowel history questions