A 32-year-old otherwise healthy nulliparous woman presented with chronic severe constipation, refractory to medical management. She reported straining and incomplete evacuation during bowel movements. Sitz marker abdominal x-rays are shown (Fig. 1). She was diagnosed with pelvic outlet obstruction constipation, and her symptoms improved with fiber supplementation and pelvic floor physical therapy (PT).
- How should patients with chronic constipation be evaluated in the surgical office setting? What are the main causes of chronic constipation?
- Which patients with constipation are appropriate candidates for surgery, and which operations should be offered?
Constipation is a substantial source of morbidity, particularly in Westernized nations. Although difficult to determine, prevalence is estimated at 9% to 20% in the United States, with higher rates in patients who are women, older individuals, and lower socioeconomic status.1 Constipation is formally defined by the Rome IV criteria (Fig. 2)2; however, as a symptom, constipation is subjective and varies significantly between patients.
Generally, patients present to a colon and rectal surgeon after an initial evaluation by primary care and/or gastroenterology. Here, we focus on the appropriate surgical evaluation.
PRESENTATION AND DIAGNOSIS
Proper identification of the etiology of constipation is essential for successful management. Diagnosis and management of constipation require time and commitment from both surgeon and patient. Presenting symptoms may vary widely among patients. Stooling may occur daily to once every several weeks. Although typically hard, some report soft, pasty, or pellet-like consistency. Other common symptoms include narrow or altered stool caliber, straining, lack of urge to defecate, inability to pass stool despite attempts at defecation, vaginal splinting, or feeling that stool is stuck.
A detailed and thorough history is the first step and must include symptom onset and duration, association with other medical conditions or medications, dietary changes, stressors, obstetric history, comorbid psychiatric conditions, and physical or sexual abuse.
In-office examination must include abdominal examination, anorectal examination, and anoscopy:
- (1) Abdominal examination should assess for distension, tenderness, surgical scars, hernias, or any palpable masses.
- (2) Anorectal examination starts with visual inspection of the anoderm and perineum for scars, perineal body bulk, fissures, hemorrhoids, and skin tags or other lesions. Digital rectal examination should assess resting and squeeze tone, pelvic floor mechanics with Valsalva, and for masses, strictures, rectoceles, or enteroceles. Any stool presence and consistency should be noted. If rectal or uterovaginal prolapse is suspected, the patient should be examined in a squatting position or straining over an in-office commode.
- (3) Anoscopy may reveal stigmata of longstanding constipation and straining, such as enlarged hemorrhoids or mucosal redundancy.
Chronic constipation may be idiopathic, but underlying causes must be ruled out. The differential diagnosis is broad (Fig. 3).
Diagnostic testing can consist of colonoscopy, imaging adjuncts, and physiology testing:
- (1) Colonoscopy is necessary to rule out mechanical obstruction from mass, polyp, or stricture. Ulceration is sometimes observed as stigmata of chronic constipation, which should prompt additional investigation for solitary rectal ulcer syndrome. Bowel preparation successfulness can be informative. Many patients can have a tortuous and redundant colon.
- (2) Imaging adjuncts can help assess motility. Ingestion of a SITZMARKS capsule (Konsyl Pharmaceuticals, Easton, MD) containing radiopaque markers and serial abdominal x-rays on days 1, 3, and 5 evaluates colonic motility. Global GI motility disorder is suggested by postprandial distension or pain, and additional studies should be ordered: a gastric emptying study, upper GI series with small-bowel follow-through, or a SmartPill Motility Testing System (Medtronic, Minneapolis, MN) study that measures pH, pressure, and transit time to provide gastric, small-bowel, and colonic emptying data.
- (3) Physiology testing may be informative. Inability to pass a 50-mm3 balloon is highly specific and 50% sensitive for pelvic outlet dysfunction. Anorectal manometry may identify a hypertrophied internal anal sphincter, suggesting chronic straining. EMG can detect paradoxical excitation of the pelvic floor during Valsalva. Cine-defecography (or dynamic pelvic MRI) evaluates defecation mechanics in real time. This may demonstrate a narrowing or no change of the anorectal angle with retention of rectal barium paste or identify concurrent rectocele, enterocele, or rectal intussusception.
Slow-transit constipation (ie, colonic inertia) is characterized by inadequate colonic motility resulting in infrequent urge to defecate and rare passage of hard stool. Retention of ≥20% of SITZMARKS markers throughout the colon on day 5 is suggestive of this diagnosis.
Pelvic outlet obstruction constipation (ie, paradoxical puborectalis function, obstructive defecation, anismus, or pelvic floor dyssynergia) is when the puborectalis paradoxically contracts or fails to relax during attempted defecation. Patients often report incomplete evacuation despite prolonged straining. Patients frequently have inconclusive workup and GI dysmotility, pelvic floor abnormalities, comorbid psychiatric conditions, situational stressors, or sexual abuse comorbidities. These patients have rectosigmoid clustering of their SITZMARKS markers on day 5.
Ultra-short-segment Hirschsprung disease is a rare cause of lifelong constipation, characterized by megacolon attributed to chronic dilation proximal to an aganglionic and short (2–4 cm) distal rectal segment. Absence of the rectoanal inhibitory reflex on anorectal manometry suggests Hirschsprung disease and should be confirmed with full-thickness rectal biopsy demonstrating aganglionosis.
Once mechanical obstruction has been ruled out, initial treatment of most patients focuses on medical management and optimizing stool texture. Bowel diaries are helpful to document symptoms and treatment response. Daily dietary fiber intake of 25 to 50 grams and 1 to 2 liters of water is recommended.3 However, those with colonic inertia may benefit from fiber restriction. Probiotics, stool softeners, laxatives, suppositories, and enemas may help; pharmacologic agents such as lubiprostone (Amitiza), linaclotide (Linzess), and plecanatide (Trulance) require careful titration and monitoring of adverse effects.
Pelvic Floor PT
Physical therapists specializing in pelvic floor anatomy and biomechanics may help patients with pelvic outlet obstruction constipation. Biofeedback and electromyographic evaluation of the pelvic floor muscles provide quantitative data to document improvement and direct ongoing therapy. Long-term efficacy of pelvic floor PT ranged from 69% to 75% in a meta-analysis of patients with obstructive defecation.4
Surgery should be reserved for patients with debilitating symptoms from constipation that have significant negative effects on their quality of life. A brief overview of the various surgical options follows.
Colostomy or Ileostomy
Patients with normal colonic transit and severe refractory pelvic outlet dysfunction constipation may benefit from end sigmoid colostomy creation. Those with concomitant slow transit constipation and pelvic dysfunction may benefit from an ileostomy.5 In addition, a loop ileostomy can be helpful in those with slow transit constipation to assess benefit before considering total abdominal colectomy.
For patients with slow transit constipation and normal pelvic floor mechanics, total abdominal colectomy with ileorectal anastomosis (TAC/IRA) can resolve constipation symptoms with improved frequency of bowel movements.6 However, symptoms of abdominal pain, bloating, and distension do not consistently improve. From a technical standpoint, total colectomy is key, because residual sigmoid colon has been correlated with worse outcomes. Although most patients with concomitant pelvic outlet obstruction have better functional outcomes with an ileostomy, those who respond well to PT and/or Botox may benefit from TAC/IRA on a case-by-case basis.7 Case series report that slow-transit patients with TAC/IRA who have persistent/recurrent constipation may experience significant improvement in quality of life with conversion to an IPAA.8
Ultra-short-segment Hirschsprung disease may require resection of the aganglionic segment with an ultra-low anastomosis. Intraoperative frozen section should be performed to localize the proximal extent of the aganglionosis. Alternatively, strip myomectomy may restore function without bowel resection and is performed by resecting a 5- to 10-mm–wide strip of internal anal sphincter from the dentate line to grossly normal, ganglionated bowel.9 Pull-through procedures (eg, Soave or Swensen) are not routinely performed in the adult population because of high morbidity and poor function.
Botulinum toxin A (Botox; Allergan, Dublin, Ireland) has shown benefit in selected patients with pelvic outlet obstruction.10 Injection into the puborectalis has been associated with improved manometric puborectalis relaxation and symptoms, although the optimal dose and timing are not well established. Patients with ultra-short-segment Hirschsprung disease may also experience symptom amelioration with intersphincteric injection of Botox.
Antegrade Colonic Enemas
Limited studies exist evaluating the benefit of cecostomy or appendicostomy creation for antegrade colonic enemas. Although a review showed that most studies found improvement, they did not show complete resolution of symptoms, and study comparison is complicated by variation in outcome measures.11
Constipated patients who seek surgical evaluation represent a diverse population. There is a wide array of underlying etiologies and extensive differential diagnoses. Diagnostic studies should be performed to rule out mechanical obstruction, categorize constipation type, and identify potentially surgically treatable causes. Treatment is individualized and generally starts with medical management with fiber supplementation to modulate stool texture. Some may benefit from other adjunctive medications and/or pelvic PT. Surgery is reserved for a highly select group, generally with either isolated colonic dysmotility or ultra-short-segment Hirschsprung disease. In the carefully selected colonic inertia patient who is refractory to medical management, TAC/IRA can result in long-lasting resolution of constipation symptoms, with 80% reporting good patient satisfaction at 3 years and some studies showing sustained benefit out to 10 years.7,12
EVALUATION AND TREATMENT ALGORITHM
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3. Anti M, Pignataro G, Armuzzi A, et al. Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation. Hepatogastroenterology. 1998;45:727–732.
4. Heymen S, Jones KR, Scarlett Y, Whitehead WE. Biofeedback treatment of constipation: a critical review. Dis Colon Rectum. 2003;46:1208–1217.
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7. Reshef A, Alves-Ferreira P, Zutshi M, Hull T, Gurland B. Colectomy for slow transit constipation: effective for patients with coexistent obstructed defecation. Int J Colorectal Dis. 2013;28:841–847.
8. Kalbassi MR, Winter DC, Deasy JM. Quality-of-life assessment of patients after ileal pouch-anal anastomosis for slow-transit constipation with rectal inertia. Dis Colon Rectum. 2003;46:1508–1512.
9. Wheatley MJ, Wesley JR, Coran AG, Polley TZ Jr. Hirschsprung’s disease in adolescents and adults. Dis Colon Rectum. 1990;33:622–629.
10. Ron Y, Avni Y, Lukovetski A, et al. Botulinum toxin type-A in therapy of patients with anismus. Dis Colon Rectum. 2001;44:1821–1826.
11. Patel AS, Saratzis A, Arasaradnam R, Harmston C. Use of antegrade continence enema for the treatment of fecal incontinence and functional constipation in adults: a systematic review. Dis Colon Rectum. 2015;58:999–1013.
12. Pikarsky AJ, Singh JJ, Weiss EG, Nogueras JJ, Wexner SD. Long-term follow-up of patients undergoing colectomy for colonic inertia. Dis Colon Rectum. 2001;44:179–183.