BOWEL PROBLEMS
| OUTCOMES AFTER SURGERY FOR CONSTIPATION —Nancy N. Baxter, MD, Assistant Professor of Surgery, University
of Minnesota Medical School, Minneapolis
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| Introductory remarks: wrong diagnosis will lead to poor outcomes in these patients; thus, important to correctly diagnose
underlying cause of constipation
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| History and physical examination: must rule out organic causes; identify exactly which medical treatments patient
has tried; differentiate obstructive defecation from slow-transit constipation; determine nature of patient’s symptoms; ask
questions related to outlet obstruction; look for evidence of diffuse motility disturbance; identify red flags indicating
problem potentially related to cancer (sudden changes in bowel habits; bleeding; occult blood loss); rule out Hirschsprung’s
disease in patients with severe constipation since early childhood; patients with weight loss or associated gastrointestinal
(GI) symptoms require additional work-up; many patients who have constipation give history of sexual
abuse (but only if asked); family history important
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| Diagnostic testing: colonoscopy not required in every case of long-standing constipation but should be considered in
patients with recent change in bowel habits or worrisome symptoms, those of screening age, or those with family history
of colon cancer; simple manometry to confirm patient has normal rectoanal inhibitory reflex; defecography to look for
causes of obstructive defecation; transit studies (eg, radiopaque markers); colonic scintigraphy (provides quantitative assessment
of colonic transit; not widely available)
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| Surgery for constipation: should be limited to those most severely affected who cannot be treated any other way (some
patients cannot be helped with medical therapy); however, of those referred to surgeons, only 10% to 20% actually have slow-
transit constipation that might require surgery; for patients who do require surgery, subtotal colectomy with ileorectal or ileosigmoid
anastomosis procedure of choice; can be open or laparoscopic
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| Outcomes of surgery for constipation: in literature, surgical outcomes generally measured by looking at relief of
symptoms, postsurgical complications (eg, incontinence), patient satisfaction, and quality of life; summary of 31 case series
of patients who underwent surgery for slow-transit constipation showed that problems with constipation resolved;
study at speaker’s institution looked at outcome in all women who had surgery for slow-transit constipation over 10-yr
period
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| Conclusion: for outcome, subtotal colectomy improves bowel movement frequency in most patients; however, functional
symptoms may persist or develop, influencing quality of life; essential that patients counseled on risks and benefits of
treatment and that medical therapies exhausted before considering surgery for constipation
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| BOWEL PREP: WHO NEEDS IT ?—Judith L. Trudel, MD, Adjunct Associate Professor of Surgery, University of Minnesota
Medical School, Minneapolis
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| Introductory remarks: recent survey of American Society of Colon and Rectal Surgeons found that >99% of surgeons
using mechanical bowel preparation to cleanse colon before elective surgery, and ≈90% felt this was important practice;
most frequently performed using oral lavage (2 most common preparations polyethylene glycol [PEG] and sodium phosphate)
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| Benefits of mechanical bowel preparation: thought to decrease incidence of infectious complications and anastomotic
leaks; easier to operate in clean colon (particularly when doing laparoscopic surgery; empty bowel easier to manipulate);
in cases where cancer or polyp difficult to identify by palpation, easy to proceed to intraoperative colonoscopy in
prepped bowel; aesthetic appeal of operating in clean colon
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| Efficacy of mechanical bowel preparation: from 1992 to 2005, number of randomized controlled studies examined
efficacy of mechanical bowel preparation for supposed benefits; infectious complications—when studies compared rates of
wound infection in patients who used mechanical bowel preparation vs those with no preparation, no difference found; 2 recent
meta-analyses concluded that use of bowel preparation resulted in slightly higher (but not statistically significant) infection
rates; intra-abdominal sepsis following surgery—studies found no significant difference between patients who used
and did not use bowel preparation; same 2 meta-analyses found patient group that lacked bowel preparation had more favorable
sepsis rate; anastomotic leaks—again, in most series, no significant difference in incidence between patient groups;
studies that reported difference found patients without bowel preparation did better in frequency of leaks; meta-analyses also
favored this patient group; bottom line—no convincing evidence from studies that mechanical bowel preparation of any
value
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| Possible risks of mechanical bowel preparation: much anecdotal evidence that mechanical bowel preparation
causes electrolyte problems, dehydration, and labile blood pressure in elderly, deconditioned, and malnourished patients;
prospective study by Kehlet et al looked at effects of preparation in 12 healthy volunteers who were well hydrated (patients
asked to drink 3 L of fluid on top of bowel preparation); results showed that preparation produced significant adverse
effects in weight loss, exercise capacity, and biochemical parameters (eg, changes in serum osmolality, urea,
electrolytes)
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| Conclusions: based on existing data, patients do not appear to benefit from mechanical bowel preparation, and its use
may be detrimental in some cases
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| INTESTINAL TRANSPLANTATION FOR SHORT-BOWEL SYNDROME —John S. Najarian, MD, Professor of Surgery,
Regents’ Professor Emeritus, University of Minnesota Medical School, Minneapolis
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| Short-bowel syndrome: occurs when patient has inadequate small bowel (usually >75% resected or lost); symptoms
include malabsorption and weight loss; occurs in children (eg, due to congenital malformations, infections) and adults
(eg, due to mesenteric vascular compromise, primary intestinal compromise, endocrine abnormalities)
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| Treatment options: total parenteral nutrition (TPN), bowel rehabilitation, or surgery; complications associated with
TPN include catheter sepsis, recurrent catheter infections, lack of vascular access, bone demineralization, electrolyte disturbances,
and eventually, liver disease; surgical approaches involving use of antiperistaltic segment, bowel-lengthening
procedure, or valve-replacement procedures proven unsuccessful
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| Living-donor intestinal transplantation: only 30 performed worldwide; during pre-cyclosporine and cyclosporine
eras, problems encountered with this operation included insufficient immunosuppression, frequent cases of rejection and
sepsis, and no standard surgical technique; at University of Minnesota, determined that successful operation required
transplantation of at least ≈200 cm of bowel
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| University of Minnesota experience: 4 living-donor intestinal transplants performed; when performing procedure,
need to leave sufficient bowel in donor; surgeon removes ileocolic artery, allowing right colic artery to remain, so donor’s ileocecal
valve and right colon will be undamaged; donor vessels anastomosed to recipient’s aorta and cava; proximal bowel
anastomosis made distal to graft ileostomy; complications associated with procedure include rejection, infection and sepsis,
and (if too much immunosuppression) posttransplantation lymphoproliferative disease
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| Comments: data from intestinal transplantation registry (Toronto); indications for living-donor intestinal transplantation
include short gut from volvulus (most common reason), ischemia, trauma, gastroschisis, desmoid tumors, pseudoobstruction,
and microvillus inclusion; causes of death include sepsis, liver failure, rejection, technical problems, renal failure,
and cardiac problems; patient survival rate (whether living or cadaveric donor) at 5 yr ≈50%
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| Summary: using standardized surgical technique (ie, 200 cm of bowel), living-donor intestinal transplantation feasible;
living-donor transplants offer logistic and immunologic advantages over transplants from cadaveric donors; operation
also option for highly sensitized patients, those with liver dysfunction, and possibly, patients facing long wait for cadaveric
donor
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| ADJUVANT THERAPY FOR RECTAL CANCER: WHEN, WHY, HOW? —Kelli M. Bullard, MD, Assistant Professor
of Surgery and Laboratory Medicine/Pathology, University of Minnesota Medical School, Minneapolis
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| Introductory remarks: over past 20 yr, numerous prospective randomized trials have proven efficacy of radiation
therapy and chemoradiation therapy in improving local control and survival after radical resection for locally advanced
rectal cancer; as experience with these has grown, clear that benefits come with some cost (specifically, chemoradiation
therapy appears to increase perioperative complications)
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| Indications for adjuvant therapy: 1990 National Cancer Institute (NCI) consensus statement recommended combined
modality therapy for all patients with stage II and stage III disease; since 1990, effort made to better define cancer
stages for tumor and nodal status to better predict which patients would benefit from adjuvant or neoadjuvant therapy;
able to identify low-risk patients with very good outcomes (stage IIA and IIIA), moderate-risk patients (stage IIB and
IIIB), and high-risk patients (stage IIIC) who tend to do poorly; discovery of low-risk patients who do well even with
node-positive disease (stage IIIA) led to question of whether these patients might benefit from surgery alone without
chemoradiation
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| Studies: stage III disease treated by surgery alone—study by Heald et al and Swedish Rectal Cancer Trial; conflicting results
on need for adjuvant radiotherapy; stage II (node-negative) disease treated by surgery alone—2 small studies suggested
patients with favorable histology might do well with surgery alone; however, adjuvant or neoadjuvant therapy still
largely recommended for stage II disease); early rectal cancer (stage I, T1-2)—clearly well managed by radical resection
alone (local recurrence rate typically <5%); however, in patients who undergo local resection for T1 and T2 lesions, local recurrence
rates extremely high (up to 67% in some series), suggesting surgery alone may not be best approach; studies on
whether these patients would benefit from postoperative chemoradiation therapy “all over the map”
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| Summary of indications: most colorectal surgeons still recommend adjuvant or neoadjuvant therapy for stage III
node-positive rectal cancer and for most patients with stage II cancer; early stage I cancers best treated with radical resection
and do not require further therapy; patients who undergo local resection may benefit (awaiting further study)
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| Preoperative vs postoperative therapy: advantages of preoperative radiotherapy—tumor shrinkage and downstaging
(may increase resectability and ability to spare sphincter); less risk to small bowel; disadvantages—probably
overtreating some patients; preoperative radiotherapy damages surrounding tissues, decreases healing, and may increase
operative difficulty; advantages of postoperative radiotherapy—accurate pathologic staging; better healing; may decrease
operative difficulty; disadvantages—delay of adjuvant therapy may result in decreased resectability of large
bulky tumors; risk for damage to small bowel and/or radiation enteritis; functional complications related to irradiating
neorectum; to date, 3 prospective randomized trials of preoperative vs postoperative chemotherapy (US studies closed
due to poor accrual; German Rectal Cancer Study Group found no difference in rates of leak, hemorrhage, or delayed
healing, but significantly greater rates of acute toxicity and stricture with postoperative therapy; in addition, preoperative
radiotherapy decreased local recurrence by 50% and increased ability to preserve sphincter)
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| Dose and timing: currently in United States, chemoradiation therapy given over period of 6 wk (total of 45-54 Gy), followed
6 wk later by total mesorectal excision (TME); in Europe, some interest in short-course radiotherapy (25 Gy of radiation
alone), followed 1 to 2 wk later by surgery; Swedish Rectal Cancer Trial reported significant decrease in local
recurrence and increase in survival with short-course radiotherapy; Dutch Colorectal Cancer Group reported similar decrease
in local recurrence but no improvement in survival
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| THE ODOR OF FLATUS AND WHAT YOU CAN DO ABOUT IT —Michael D. Levitt, MD, Professor of Medicine,
University of Minnesota Medical School, and Associate Chief of Staff for Research, VA Medical Center, Minneapolis
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| How humans detect odor: olfactory area in upper part of nasal cavity contains layer of mucus that contains millions of
cilia; cilia have receptors for various chemicals; do not smell anything until volatile chemical reacts with receptor on cilia;
how one breathes determines how well one can detect odors (eg, little turbulence in cilia during exhalation [why we do not
smell our own breath] and inhalation; sniffing causes greater turbulence and contact with cilia); each cilium has many receptors
specific for any given chemical; when cell fires and impulse goes to brain, brain understands exactly which chemical
stimulated cell; cell and receptors under control of single gene; ability to smell genetically controlled; ≈1000 different
genes and olfactory cells enabling ≈1000 different odors to be detected
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| Compounds that cause noxious odor from intestinal gas: placed rectal tube in 6 female and 10 male volunteers
and captured gas in aluminum foil bag (men pass larger volumes of flatus than women; average amount 119 mL for men,
88 mL for women); noxious gases in highest concentration sulfur compounds (ie, hydrogen sulfide, methane sulfide, and
dimethyl sulfide); total amount of noxious gas per pass 4 µL (<0.001% of flatus); used blinded judges to sniff gas in randomized
fashion and rate its odor, then correlated noxiousness of odor with concentration of sulfide gases in flatus;
treated flatus samples with zinc to remove sulfide gases and found that odor decreased significantly; sulfide gases important
but not only compounds that cause noxious odor
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| Sex difference in odor: flatus passed by women tended to have worse odor and higher concentrations of sulfide gases,
compared to that of men
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 | Bismuth: effectively binds sulfide gases; reduces ability of feces to release sulfide gases; could be used short term but not
recommended for long term
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| Charcoal: effectively absorbs every odoriferous compound, but oral charcoal ineffective at decreasing or eliminating odor
of flatus; various external charcoal devices available, eg, cushions, underwear, pads; speaker studied each of these and
found cushions removed ≈20% of gas, pads removed 60% to 80%, and spun-charcoal underpants removed 100%
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Educational Objectives
| The goal of this activity is to provide listeners with a better understanding of some of the problems encountered in colon
and rectal surgery, especially related to the management of constipation, mechanical bowel preparation, short-bowel syndrome,
rectal cancer, and flatus. After hearing and assimilating this program, the clinician will be better able to:
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| 1. Diagnose the underlying cause in patients with long-standing constipation.
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| 2. Counsel patients on the risks and benefits of surgical treatment for constipation.
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| 3. Discuss the scientific evidence on the role and possible adverse effects of mechanical bowel preparation in patients
undergoing elective colorectal surgery.
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| 4. Describe the standard surgical technique for living-donor intestinal transplantation, the potential problems associated
with this procedure, and the indications for its use in patients with short-bowel syndrome.
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| 5. Describe the current methods for decreasing the odor of flatus and list the efficacy of each.
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Discussed on This Program
Azathioprine (AZA) [Imuran]
Cyclosporine (cyclosporin A) [Gengraf, Neoral, Sandimmune]
Dibasic sodium phosphate and monobasic sodium phosphate enema [Fleet]
Mycophenolate mofetil (MMF) [CellCept]
Polyethylene glycol-electrolyte solution (PEG-ES) [GoLYTELY, NuLytely, OCL]
Prednisone [Deltasone, Liquid Pred, Meticorten, Orasone, Panasol-S, Prednicen-M, Prednisone Intensol Concentrate,
Strerapred DS]
Tacrolimus (FK506) [Prograf, Protopic]
Suggested Reading
Abu-Elmagd KM: Intestinal transplantation for short bowel syndrome and gastrointestinal failure: current consensus, rewarding
outcomes, and practical guidelines. Gastroenterology 130(2 Suppl 1):S132, 2006; Arnoletti JP, Bland KI: Neoadjuvant
and adjuvant therapy for rectal cancer. Surg Oncol Clin N Am 15:147, 2006; Birgisson H et al: Swedish Rectal
Cancer Trial Group. Adverse effects of preoperative radiation therapy for rectal cancer: long-term follow-up of the Swedish Rectal
Cancer Trial. J Clin Oncol 23:8697, 2005; Bucher P et al: Mechanical bowel preparation for elective colorectal surgery:
a meta-analysis. Arch Surg 139:1359, 2004; Cecil TD et al: Total mesorectal excision results in low local recurrence rates in
lymph node-positive rectal cancer. Dis Colon Rectum 47:1145, 2004; Das P, Crane CH: Preoperative and adjuvant treatment
of localized rectal cancer. Curr Oncol Rep 8:167, 2006; FitzHarris GP et al: Quality of life after subtotal colectomy
for slow-transit constipation: both quality and quantity count. Dis Colon Rectum 46:433, 2003; Folkesson J et al: Swedish
Rectal Cancer Trial: long lasting benefits from radiotherapy on survival and local recurrence rate. J Clin Oncol 23:5644, 2005;
Gopaul D et al: Outcome of local excision of rectal carcinoma. Dis Colon Rectum 47:1780, 2004; Goulet O, Sauvat F:
Short bowel syndrome and intestinal transplantation in children. Curr Opin Clin Nutr Metab Care 9:304, 2006; Gunderson
LL et al: Rectal cancer: Preoperative versus postoperative irradiation as a component of adjuvant treatment. Semin Radiat Oncol
13:419, 2003; Holte K et al: Physiologic effects of bowel preparation. Dis Colon Rectum 47:1397, 2004; Iannelli A et
al: Laparoscopic subtotal colectomy with cecorectal anastomosis for slow-transit constipation. Surg Endosc 20:171, 2006;
Jackson C, Buchman AL: Advances in the management of short bowel syndrome. Curr Gastroenterol Rep 7:373, 2005;
Kalbassi MR et al: Quality-of-life assessment of patients after ileal pouch-anal anastomosis for slow-transit constipation
with rectal inertia. Dis Colon Rectum 46:1508, 2003; Korkolis DP et al: Short-term preoperative radiotherapy is a safe approach
for treatment of locally advanced rectal cancer.Int J Colorectal Dis 21:1, 2006; Levitt MD et al: Evaluation of an extremely
flatulent patient: case report and proposed diagnostic and therapeutic approach. Am J Gastroenterol 93:2276, 1998;
Lundin E et al: Outcome of segmental colonic resection for slow-transit constipation. Br J Surg 89:1270, 2002; Ohge H et
al: Effectiveness of devices purported to reduce flatus odor. Am J Gastroenterol 100:397, 2005; Pasetto LM: Preoperative
versus postoperative treatment for locally advanced rectal carcinoma. Future Oncol 1:209, 2005; Petersen S et al: Is surgery-only
the adequate treatment approach for T2N0 rectal cancer? J Surg Oncol 93:350, 2006; Ram E et al: Is mechanical
bowel preparation mandatory for elective colon surgery? A prospective randomized study. Arch Surg 140:285, 2005; Rao SS:
Constipation: evaluation and treatment. Gastroenterol Clin North Am 32:659, 2003; Rothenberger DA et al: Are we
overtreating some patients with rectal cancer? Oncology (Williston Park) 18:1789, 2004; Slim K et al: Meta-analysis of randomized
clinical trials of colorectal surgery with or without mechanical bowel preparation. Br J Surg 91:1125, 2004; Suarez
FL, Levitt MD: An understanding of excessive intestinal gas. Curr Gastroenterol Rep 2:413, 2000; Wang SF et al:
Treatment of short gut syndrome with early living related small bowel transplantation. Transplant Proc 37:4461, 2005; Wille-
Jorgensen P et al: Clinical value of preoperative mechanical bowel cleansing in elective colorectal surgery: a systematic review.
Dis Colon Rectum 46:1013, 2003; Zmora O et al: Trends in preparation for colorectal surgery: survey of the members
of the American Society of Colon and Rectal Surgeons. Am Surg 69:150, 2003.
Faculty Disclosure
In adherence with ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the faculty reported
nothing to disclose.
Drs. Baxter and Trudel spoke at the 68th Annual Colon and Rectal Surgery: Conundrums and Controversies, held September
8-10, 2005, in Minneapolis, MN and sponsored by the University of Minnesota Medical School, Colon and
Rectal Surgery Associates, Ltd., and the Minnesota Colon and Rectal Foundation. Drs. Najarian, Bullard, and Levitt
appeared at the 69th Annual Advances in Gastrointestinal and GI Laparoscopic Surgery, held June 15-18, 2005, in Minneapolis
and sponsored by the University of Minnesota Medical School. The Audio-Digest Foundation thanks the
speakers and the sponsors for their cooperation in the production of this program.
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