Constipation Clinical Presentation

Basing the diagnosis of constipation on simply asking the patients whether they are constipated is associated with marked underreporting of the problem in patients who have physical evidence of constipation, such as the presence of hemorrhoidal disease.^[8] Accordingly, a careful history must be obtained, including inquiries into current medications (including over-the-counter, herbal agents, and prescription medications), previous colonoscopy, and any other medical problems present.

A constipated patient may be otherwise totally asymptomatic or may complain of 1 or more of the following:

• Abdominal bloating
• Pain on defecation
• Rectal bleeding
• Spurious diarrhea
• Low back pain

The following also suggest that the patient may have difficult rectal evacuation:

• Feeling of incomplete evacuation
• Digital extraction
• Tenesmus
• Enema retention

The following signs and symptoms, if present, are grounds for particular concern:

• Rectal bleeding
• Abdominal pain (suggestive of possible irritable bowel syndrome [IBS] with constipation [IBS-C])
• Inability to pass flatus
• Vomiting
• Unexplained weight loss

The history should begin with a detailed inquiry into the patient’s normal pattern of defecation, the frequency with which the current problem differs from the normal pattern (eg, “missing a day”), the perceived hardness of the stools, whether the patient strains in order to defecate, and any other symptoms the patient may be experiencing.

An inquiry concerning the amount of time spent on the toilet while waiting to defecate may also be illuminating. Patients should be asked to describe in detail what happens when they try to defecate and what maneuvers (pharmacologic or physical) they have used to facilitate this process. The answers to these questions may suggest chronic laxative abuse or less common causes, such as colonic outlet obstruction.

The duration of the problem is important. In adolescents or young adults, the duration of the problem may differentiate congenital defects from acquired causes. Neoplastic obstruction is less likely in younger patients or in patients older than 50 years who have had symptoms for at least 2 years and/or have recently had a screening colonoscopy. However, colon cancer certainly occurs in younger adults and even rarely in teenagers, while a previous screening colonoscopy may have missed a neoplasm.

The onset of symptoms is also very important, in that intestinal obstruction can present as acute constipation. In the hospital setting, ileus from another illness or Ogilvie syndrome should also be considered. Questions regarding the onset of constipation may provide useful etiologic information, whether in terms of changes in diet, new medications, or associated psychosocial difficulties at that time.

In addition to defining the nature of the patient’s bowel habit, it is necessary to try to identify the factors likely to be responsible for the abnormal bowel habit. Most patients who are constipated consume either too little fiber or too little water; therefore, assessing the patient’s diet is useful. For acute changes in the bowel habit, a parallel dietary change should be ascertained.

Learning how much fluid and what types of fluids the patient drinks on an average day is important. Epidemiologic studies have clearly established a link between coffee consumption and worsening constipation. The diuretic effects of coffee, tea, and alcohol are likely counterproductive. Milk products may cause constipation in some individuals.

The state of patients’ bowel motility represents a balance between factors that promote motility and factors that inhibit it. The most important influencing factor is exercise, which stimulates bowel motility. Conversely, narcotics, antipsychotic agents, and other constipating medications reduce motility. Diuretics or substantial amounts of coffee, tea, or alcohol decrease available water to the colon. Chronic laxative abuse also causes refractory constipation.

If the patient shows evidence of diseases or symptoms associated with constipation, such as diverticular disease, hemorrhoids, anal fissures, or fistula in ano, delineating these conditions historically and determining the nature of any previous therapy for them is appropriate. For instance, patients with hemorrhoids may neglect to mention that they were previously treated for this problem or that they have been receiving medications for constipation for several years.

Rectal bleeding should be taken seriously and evaluated carefully, particularly in patients who are older than 50 years or have a family history of colorectal disease. Patients with hemorrhoids may also have rectosigmoid cancer. Both cancer and hemorrhoids can produce bright red blood from the rectum. Most patients older than 50 years or with a family history of colorectal disease should be screened for colorectal cancer. A full colonoscopy is preferable, although in some cases flexible sigmoidoscopy or barium enema may be used if colonoscopy cannot be achieved. The role of CT colography in this setting awaits definition, although it offers an attractive alternative in the patient in whom colonoscopy is attempted and fails.

Finally, the evaluation should include the patient’s description of the act of defecation. Pain during defecation might suggest a fissure or tenesmus from a rectal tumor. Painless inability to pass an otherwise soft stool suggests a rectal outlet obstruction.

Neurologic and endocrine disorders also can cause constipation. Most notably, diabetes may be associated with chronic dysmotility. Patients with hypothyroidism may exhibit decreased motility and slow transit times.^[9] Patients with panhypopituitarism, pheochromocytoma, or multiple endocrine neoplasia 2B are also at risk for constipation. When no other cause can be determined, a careful endocrine review is particularly important for patients with a recent onset of constipation and for patients who are refractory to conservative treatment.

Similarly, central nervous system (CNS) diseases, such as Parkinson disease, multiple sclerosis, stroke, CNS syphilis, and spinal injury or tumors, may cause constipation and should be considered in the patient’s history and evaluation.

Some cases of constipation may have a psychogenic component. On one hand, constipation is a frequent somatic expression of psychological distress; on the other, constipation itself may give rise to psychological disturbances.

A history of sexual abuse is observed with unusual frequency in patients who are chronically constipated, particularly those with anismus. A history of other psychological abnormalities is often found, particularly among patients who are refractory to medical treatment and have normal bowel transit times and normal results from anorectal studies.

Such factors should be gently explored in patients in whom first-line conservative treatment has failed. Psychiatric referral may be appropriate in such patients when medical evaluation and therapy have been exhausted or when gentle questioning reveals some unexpected information.

General physical examination often is of no benefit in determining etiology or deciding on treatment. In addition to the general evaluation, the abdomen, pelvis, and rectum, specifically, should be physically examined. Both the cause of constipation and its effects should be sought.^[8]

Abdominal distention or masses may indicate the presence of colonic stools or tumors. Large abdominal wall hernias, especially ventral hernias, may interfere with generation of the intra-abdominal pressure required for the initiation of defecation. Rarely, a left-sided sliding inguinal hernia with an incarcerated sigmoid colon may cause difficulties in bowel movements.

It was once widely held that elderly patients with new inguinal hernias should be assumed to have occult constipation due to partially obstructing colonic neoplasms and that those patients therefore required colorectal cancer screening. At present, the requirement for colorectal cancer screening in such patients remains controversial. The pathophysiology underlying a link between colonic neoplasms and hernias is unknown, because the lesions detected on screening are early lesions and are unlikely to have caused constipation.

Pelvic examination in women should specifically address the posterior vaginal wall, with particular attention to any evidence of internal prolapse or rectocele. This region should be palpated while the patient is at rest and then while she is straining to defecate. Many women with rectocele do not experience constipation. Good surgical results are not guaranteed, and a thorough preoperative workup to rule out other potential causes of constipation should always be performed.

During the anorectal examination, the patient should be assessed for the following:

• Perianal excoriation
• Skin tags/hemorrhoids
• Anal fissure
• Anocutaneous reflex
• Prolapse during straining
• Stool amount and consistency - More stool is present within the rectal vault in pelvic outlet dysfunction than in colonic inertia or IBS, in which little or no stool remains in the rectum between defecations; pelvic floor dysfunction is manifested by failure of descent of the examining finger and contraction of the upper segment of the sphincter during straining

Digital rectal examination provides information about the following:

• Anorectal masses
• Tone of the internal anal sphincter
• Strength of the external anal sphincter and puborectalis muscle
• Presence of a rectocele (an outpouching usually present in the anterior rectal wall)
• Presence of gross blood or occult bleeding by checking the stool guaiac
• Presence of fecal impaction

The anorectal examination should attempt to ascertain the cause of the constipation. Causes that may be defined include the following:

• Anal fissure, particularly in children who retain their feces in order to avoid painful defecation
• Anal stenosis
• Partially obstructing rectal masses
• Rectal prolapse

Rectal prolapse may be either external or internal. The anus should be carefully examined for prolapse at rest and during a Valsalva maneuver. Care should be taken to distinguish a true full-thickness rectal prolapse from a mucosal prolapse, which is unlikely to cause constipation. Asking the patient to perform a Valsalva with the examining finger in the rectum in order to seek evidence of an internal prolapse may be worthwhile, although this is a relatively insensitive way of diagnosing prolapse.

In contrast to inguinal hernias, rectal prolapse is typically related to constipation. At least 1 retrospective study has demonstrated a strong association between rectal prolapse and rectosigmoid neoplasms in patients older than 50 years. Sigmoidoscopy is probably indicated for these patients, and full colonoscopy should be performed if they are otherwise due for colorectal cancer screening.

In addition to delineating the cause of the constipation, the anorectal examination should be used to determine the effects of the constipation. The presence of fissures or fistulae, any evidence of scars from previous perirectal abscess drainages or other surgeries, and the nature of the patient’s hemorrhoidal columns should be noted and characterized. Enlarged hemorrhoids do not require treatment unless they cause symptoms.

Although the effectiveness of fecal occult blood testing has been hotly debated, performing such a test after a rectal examination in patients older than 50 years is probably worthwhile. The presence of blood in the stool warrants further evaluation. Never assume that the patient is bleeding from hemorrhoids or fissures until other sources of bleeding have been ruled out.

A complete physical evaluation of the patient should also include a search for evidence of systemic diseases that may be contributing to constipation. Such systemic diseases include the following:

• Endocrine dysfunctions (eg, hypothyroidism, hypopituitarism, and diabetes mellitus)
• Neurologic abnormalities (eg, brain or spinal cord injury, peripheral neuropathy, multiple sclerosis, and Parkinson disease)

Difficulty in defecation may cause substantial discomfort, abdominal cramping, and a general feeling of malaise.

Actual or perceived constipation typically results in self-medicating with various laxatives. Although laxatives may correct the acute problem, chronic use of these agents leads to habituation, necessitating ever-increasing doses that result in drug dependency and, ultimately, a hypotonic laxative colon. Melanosis coli from prolonged laxative use is an incidental finding at endoscopy.

Acute or chronic episodes of straining may cause acute or chronic hemorrhoidal disease (characterized by pain, itching, or bleeding) or acute hemorrhoidal thrombosis (characterized by intense pain and acute engorgement of 1 or more of the hemorrhoidal columns). Generally, hemorrhoids are medically managed; surgical intervention is reserved for when medical management fails.

Whether constipation actually causes hemorrhoidal disease is viewed as controversial by some authors. However, upon careful questioning, these patients frequently provide a history of recent defecatory difficulties, most commonly constipation related, although less commonly diarrhea related (with the exception of patients in the early postpartum period). Furthermore, conservative management of hemorrhoidal disease is more likely successful when future straining is prevented.

The passage of hard stools may result in an acute anal fissure, which is a painful tear in the anoderm that may bleed. The regular passage of hard stools and the painful anal spasms during defecation that impinge the hard stools against the fresh wound prevent the anal fissure from healing. Generally, fissures are medically managed. In addition to local wound care and analgesia, softening of stools is essential for successful management. Surgical intervention is reserved for when medical management fails.

Constipation may be one cause of pelvic floor damage in women. Using structured questionnaires, Amselem et al determined that 61 out of 596 women (10%) attending a gynecologic clinic had pelvic floor damage; constipation was present in 19 of the 61 (31%), rivaling the frequency of obstetric trauma (also 19 women) among these patients.^[10]

Amselem et al also determined that of the 535 women without pelvic floor damage, 86 (16%) had constipation and 83 (15.5%) had obstetric trauma.^[10] Employing univariate analysis, they reported odds ratios of 2.36 for constipation and 2.46 for obstetric trauma associated with pelvic floor damage. On the basis of their data, the authors suggested that constipation and obstetric trauma are equally important in the development of pelvic floor damage.

The chronic pressure effect of hard stools against the anterior rectal wall when the patient strains during defecation is believed to cause solitary rectal ulcers. This is usually a self-limiting process and responds to treatment of constipation. In adults, surgical or gastroenterologic consultation may be required to differentiate benign solitary rectal ulcers from rectal malignancy.

Other complications of constipation may include the following:

• Fecal impaction
• Bowel obstruction
• Fecal incontinence
• Stercoral ulceration/perforation
• Megacolon
• Volvulus
• Rectal prolapse
• Urinary retention
• Syncope
• Fistula in ano