Bowel prep for endometriosis surgery remains a debated topic.

Date: Sun, 27 Jan 2013 07:41:06 -0500 Larry R Glazerman wrote

There was an interesting paper in Fertility and Sterility in 2006 (Muzii et al. Bowel preparation before laparoscopy, Fertility and Sterility Vol. 85, No. 3, March 2006) that assessed visualization of the surgical field as a primary endpoint. Surgeons were blinded to whether the patient had a bowel prep. Their conclusion:

Bowel preparation with oral NaP does not offer any significant advantage in patients undergoing laparoscopy for benign gynecologic conditions. In addition, MBP significantly increases preoperative discomfort.

Regarding bowel prep and bowel injury, my recommendation to my residents always has been to find out where their local general or colon-rectal surgeons stand. If the surgeon would open someone who had an injury to an unprepped bowel, I’d prep these patients. If the surgeon agrees with the current literature that bowel prep isn’t necessary, I wouldn’t.

Larry R. Glazerman, MD, MBA, FACOG, Department of Obstetrics and Gynecology, Mainline Health,

Reply by Jason Abbott (Associate Professor Jason Abbott,  School of Women’s and Children’s Health, University of New South Wales, Sydney, Australia)

Our group has just completed the fourth RCT of bowel preparation at gynaecological laparoscopy. This will be published in Obstetrics and Gynaecology in March this year. The findings from our’s and other studies in gynaecological laparoscopy:

Muzii et al 2006 Mechanical bowel preparation (oral NaP solution) vs no mechanical bowel preparation 140 women
• No difference in surgical field, operative difficulty, operative time, and postoperative complications between two groups
• Mechanical bowel preparation increases patient discomfort
• Mainly diagnostic or adnexal surgery
• High conversion rate to laparotomy
Lijoi et al 2009 Mechanical bowel preparation (oral NaP solution) vs 1 week low-fiber diet 64 women
• No difference in surgical field between two groups
• More patient discomfort in mechanical bowel preparation with oral NaP group
• 1week low fiber diet may be difficult to achieve for patients
• No control group
• Exclusion of patients with previous surgery, body mass index greater than 30, rFASrAFS stage III-IV endometriosis

Yang et al 2011 Mechanical bowel preparation (oral NaP solution) vs. single NaP enema 133 women
• No difference in surgical field, bowel handling, degree of bowel preparation, surgical difficulty
• More patient discomfort in oral NaP group with more abdominal bloating, swelling, weakness, thirst, dizziness, nausea, fecal incontinence and overall discomfort
• No control group

Won et al (our group to be published shortly) Mechanical bowel preparation (oral NaP solution) vs. 2 days minimal residue diet vs. no mechanical bowel preparation 257 women
• No clinical difference in surgical view and bowel handling between all three groups
• More patient discomfort in mechanical bowel preparation group and minimal residue diet group
• Acceptable for women with suspected pathology in posterior compartment without compromising surgery
• 2 methods of bowel preparation compared to a true control group
• Bowel function followed up for 1 month postindex surgeryData from metanalyses performed in the general surgical literature do not support bowel preparation as a mode of reducing bowel complication risk.
At least for complex gynaecological laparoscopy, even in the deep posterior compartment for advanced endometriosis (stage IV) we found no clinical difference for view, bowel handling or completion of surgery. Given that women do feel worse when using mechanical bowel preparation and in light of all RCT’s for gynaecological surgery providing the same outcome for all approaches, the evidence is against using bowel preparation.

Jim Kondrup

Well how timely is this. I just gave a complications lecture for the SAAOG conference at the Greenbriar in WV. When I discussed bowel prep I was challenged with “evidence based medicine.” Several of the surgeons did not agree with my practice of prepping just about all of my patients. One surgeon stated that he was at a trauma center and his surgeons assured him they would primarily close a bowel injury. Well not at my place. Our surgeons have different views depending on who you speak too. Some quote, “minimal spillage.” What does that mean? Try sewing a bowel hole as gross stool pours out and you have to suction the stool constantly and take her out of trendelenburg to keep the spillage from going up.

Nothing like waking up with a diverting colostomy to strengthen the surgeon-patient relationship. Guarantee she will be taking photos of that for possible future reference. I bowel prep everyone and will continue to do that. I “know” I see better and the few times I have been in the bowel I have not had to do colostomy because all was clean.

When the general surgeon says, “open and colostomy” you won’t be in a position to quote evidence based medicine.

   31 Jan 2013 19:42:39 -0500  Jason Abbott

To Harry: more than 50% of women in each group had endometriosis that was clinically detectable in the posterior compartment with 1/3 of these having stage IV disease. Planned bowel resection for endometriosis was an exclusion criteria, since the numbers would not be there and this work had already been done in the surgical fields. The emphasis was on dissection in the posterior compartment (endometriosis, myomectomy, hysterectomy) for this study, since these data were missing from previous works. The combined gynaecological and general surgical data have all demonstrated that bowel preparation does not impact the performance of surgery or decrease leakage when bowel resections (surgical studies) are performed.

To Jim: If you feel that you know you see better then that is your prerogative. However, in our blinded (and the other blinded) studies this was not demonstrated. There were a very small but equal number of cases of ‘poor vision’ from a full bowel in the patients who had bowel preparation compared with none. The vast majority of patients had good to excellent surgical field, regardless of their bowel prep allocation group. This of course is the value of blinding and the validation of our profession. Science must be the arbiter of clinical practice, since to submit to opinion and feeling would result in clinical chaos.

The evidence is published and I will follow it and encourage others to do the same, or to disprove this overwhelming body of science.


Date: Thu, 31 Jan 2013 19:43:22 -0500   Bill Parker

Thank you Jason for the excellent review of the evidence. Jim, what is the point of evidence-based medicine if you “know” you are right. I imagine Jason’s study was blinded, so that indicates no improved visualization. In addition, general surgeons have excellent evidence in their own literature that the outcomes of bowel repair are not better after a prep, and patients hate the prep (having had 3 myself for colonoscopies, I can speak to this personally!) and come to the OR dehydrated. You might consider going over the evidence with your general surgeons before you get into this situation again. That’s what we did and we have not used a bowel prep in years.

Date: Thu, 31 Jan 2013 19:43:46 -0500  From: Jon Einarsson

I wanted to congratulate Dr. Abbott and colleagues for putting yet another nail in the coffin of mechanical bowel preps (mbp). Unfortunately there are a lot of surgeons who don’t believe in “evidence based medicine”. I will be the first to admit that “evidence” in gynecologic surgery is subject to a number of biases with one of the main confounders being the surgeon.

However, to summarize the available evidence regarding the use of mbps in gynecologic surgery, this is it; evidence supporting benefit to patients or surgeons = ZERO. I can also quote my anecdotal evidence and say that I have cut into the bowel (large and small) several times in non-prepped patients and they have done very well with a primary repair (by me).

I do agree with Dr. Kondrup that a discussion with the consulting general surgeon about “evidence based medicine” in the OR is not going to be helpful, so I would encourage everyone to have this discussion beforehand. Finally, please keep in mind that there are laywyer web sites advertising to get a hold of “victims of mechanical bowel preps”. As more and more “evidence” accumulates against the routine use mbps, you as the surgeon could be in an uncomfortable position if your patient ends up in renal failure due to the routine use of a mbp.

Date: Thu, 31 Jan 2013 19:45:16 -0500  Kurian Thott

I see that bowel prep debate will be a nebulous area of discussion for  some time and I’m not convinced that there will ever be enough true data to convince anyone of what to do for their patient.This may go in the ‘do you close peritoneum at c-section’ argument. And we all know where that goes! I agree with the docs that do use bowel prep, not so much for bowel injury reasons as most of what is in the small intestine is considered sterile. But for visualization, as most MIGS surgeons on here would agree there’s never enough T-burg and that gas filled loop of bowel always seems to finds its way into the line of fire. But I’m sure we’ll continue the debate 🙂

Date: Mon, 4 Feb 2013 19:21:23 -0500 Matthew Siedhoff    University of North Carolina at Chapel Hill,

I am glad to hear that the issue of mechanical bowel prep is being investigated with controlled trials and congratulate Dr. Abbott’s group. We are also in the midst of such a trial, about 2/3 through recruitment. The issue regarding adequate power is correct. If you are most interested in complications, then yes, it would take thousands of subjects to answer the question, a situation that occurs any time the outcome is rare (e.g. surgeons still are debating the relative safety of different methods of obtaining laparoscopic access). However, the issue of safety seems to have been fairly definitively answered with the trauma literature demonstrating that primary reanastamosis can be performed in resection during emergent laparotomies. We elected to study the subject using a similar outcome to the the folks at UPMC who compared oral and enema prep and concluded that there’s not a difference in visualization but subjects prefer enema to oral preparation.

The issue about suturing or stapling over stool is a little different, but, if that is a concern, one can have the patient empty the colon (e.g. dulcolax the night before surgery) without needing to do a full colonoscopy-style prep.

I think there are many areas we can work to improve perioperative care, including things like perhaps earlier catheter removal, relaxing rules on long periods of NPO prior to surgery, etc. The direction of change is not always toward looser recommendations–for example, surgeons are probably more meticulous about antibiotic and VTE prophylaxis than they were a decade ago and that probably results in fewer complications. But not asking the questions in deference to historical practice doesn’t seem to be the best solution.

Date: Sun, 3 Feb 2013 12:27:51 -0500 Tom Lyons

Congratulations to Jason on a very well presented piece of data. I think that without question mechanical bowel prep is no longer indicated by the evidence. I agree that the best avenue is a discussion with your general and colorectal colleagues before making a change. as this could be consequential in the ongoing care of your patients.

I would make one other medico-legal observation.  If a patient undergoes mechanical bowel prep, it is difficult for that patient to claim that she was not informed of the possibility of bowel damage at their surgical procedure. This doesn’t seem like much but plaintiff attorneys certainly seem to treat it as if it were. Of course good documentation of consent in the record can preclude this issue but it deserves mention in this discussion.

Date: Sun, 3 Feb 2013 12:28:02 -0500  Larry R Glazerman

Great discussion about bowel prep. Kudos to Dr. Abbott for his controlled trial. Based on this and other papers, I have recently stopped doing bowel preps. I agree strongly, however, with those who recommend consulting in advance with the general surgeons. If your local surgeon doesn’t believe or doesn’t abide by this evidence, and would do a colostomy for an injury on an unprepped colon, then you as the gyn surgeon are between a rock and a hard place, and I’d agree that in this situation bowel prep, notwithstanding the evidence, is the better part of valor.


Date: Sun, 3 Feb 2013 12:28:18 -0500 David Redwine

I am now retired, but during my very active career in performing endometriosis surgery, I performed over 1,000 cases of intestinal endometriosis, including several hundred segmental resections. I did not do routine bowel preps on all patients, so I certainly agree with the trend against routine bowel preps, having anticipated this trend by several decades. I did use an individualized approach, however, since if a segmental bowel resection is performed, it can be a disgustingly messy event if the rectosigmoid is full of stool. This criterion was apparently not included in studies regarding routine bowel preps. It is a significant criterion in my opinion. If you have ever had to empty the descending colon of stool during surgery, you will understand why. My individualized criteria for bowel preps were the following:

1. presence of ovarian endometriomas - since this increases the chance of significant intestinal involvement. (1) 2. previous surgery in which cul de sac obliteration was diagnosed - again, a 70% chance of some surgery being required on the bowel 3. presence of significant nodularity on exam - this could imply cul de sac obliteration, which carries a 70% chance that something will need to be done to the rectum to remove endometriosis. (2) 4. previous surgery in which an intestinal nodule of endometriosis was identified.

Using these criteria, I almost never had to do a segmental bowel resection on an unprepped bowel, so they served me well. Given the tertiary referral nature of my practice, I estimate that about 40% of my patients were bowel prepped. About 28% of my patients had some degree of intestinal involvement, so a certain % of patients who didn’t need bowel preps wound up having bowel preps.

In other words, if I considered the risk of intestinal involvement requiring a full-thickness or segmental resection to be elevated, I would have the patient do a mechanical bowel prep. Mechanical bowel preps are good for eliminating stool, but some patients do not complete them, or don’t do them at all but say they did. Plus, liquid remaining in the bowel can leak out and contaminate the pelvis and abdomen, with risk of an abscess. So a bowel prep isn’t magic or a guarantee against a complication.

On the other hand, if I came across endometriosis of the bowel in an unprepped patient, I would go ahead and remove the endometriosis since most patients with intestinal endometriosis do not require a full thickness or segmental resection. Many patients can be treated by partial thickness resection or mucosal skinning without entering the bowel lumen. If a full-thickness disk resection of the colon was necessary in a patient with unprepped bowel, I would do that as well. Solid stool within the bowel will stay in place and not leak out.

So, I agree that routine bowel preps for gyn laparoscopy are unnecessary in the patient populations treated by most gynecologic surgeons. As the lines between gyn surgery and other surgical specialties begin to blur in endometriosis patients, gyn surgeons will increasingly be called upon to perform bowel surgery (3). For those surgeons with a referral practice for surgical treatment of endometriosis, individualized bowel preps will remain helpful for the reason I stated above.


1. Redwine DB. Ovarian endometriosis: A marker for more severe pelvic and intestinal disease. Fertil Steril 1999;73:310-5.
2. Redwine DB, Wright J. Laparoscopic treatment of obliteration of the cul de sac in endometriosis: Long term followup. Fertil Steril 2001;76:358-65.
3. Peireira R, Zanatta R, Redwine DB. The feasibility of laparoscopic bowel resection performed by a gynecologist to treat endometriosis. Curr Opin Obstet Gynecol 2010, 22:344 – 53.


Date: Sun, 3 Feb 2013 12:28:32 -0500  Ken Sinervo 

First I would like to comment on the concerns I have with several of the studies mentioned regarding bowel preps.

The Muzii study did not deal with patients with advanced disease within the cul de sac and there was a high rate of conversion to laparotomy. This suggests that the pathology being dealt with was minimal and does not lend itself well to patients with possible bowel involvement in which potential bowel injury is more likely.

The Lijoi study excluded patients with previous surgery (that would be over 75% of our patients) and patients with stage III-IV endo (again patients more likely to require bowel dissection and be at risk for bowel injury).

Finally, while the design of Dr. Abbott’s study is very good, it does not really address the most important issue - what is done if there is an injury. This is at the discretion of the general surgeons that you work with and at my center, the majority would still be inclined to perform colostomy than primary repair with a non-prepped bowel and would do a primary repair on prepped bowel.

We have had 2 inadvertent bowel injuries that required repair in over 3500 laparoscopies with only 2 conversions to laparotomy (neither of the injuries was converted) (with over 1000 with stage IV endo and 200 bowel resections), so to demonstrate a difference in outcomes following injury with or without bowel prep would likely require over 20,000 patients.

While I acknowledge that there is more discomfort with a bowel prep, I feel that it is still worth the discomfort to minimize morbidity from a bowel injury. While I rarely do not perform a prep, compared to when I trained and we did not routinely use bowel prep, I feel that it does aid in visualization.


Date: Sun, 3 Feb 2013 12:28:44 -0500 Martin Robbins   New England Center for Endometriosis

Excellent discussion. Just my opinion, but AAGL has been the most relevant medical organization and the AAGL Listserve continues to be one of the best educational tools that have helped me in my nearly 30 years of practice.My practice focuses on excision of endometriosis. Therefore, I excise lesions and invasive nodules from small bowel, sigmoid, rectum, and bladder.
At our medical center, the general surgeons and colorectal surgeons are using mechanical bowel preps. In addition, to try to further reduce infections and peri-operative morbidity, the surgeons have added oral antibiotics to the preop bowel preps and intra-operative IV antibiotics during cases where bowel resection is done.
The colorectal surgeons say that there is a small percentage of leaks from bowel repairs that occur despite their best efforts.The review of the past studies and the current study by Dr. Abbott is excellent.
I have not bad a problem with the bowels I have repaired, but I have no way of knowing whether the Preop bowel prep did or did not make a difference.
In up to 50% of cases of surgically proven intestinal endometriosis, it is not known preoperatively. So as an endometriosis surgeon I want to be prepared.
Planned bowel resection for endometriosis was a criterion for exclusion in the study, per Dr. Abbott.
If a rare leak were to occur, there is the medical-legal concern of whether a bowel prep might have reduced morbidity. According to the literature presented, the prep may not have made a difference, but the issue would come up. Therefore, when practicing at a good medical center where the surgeons are doing, and the Department of Surgery advocates, bowel preps, I think I will continue to do them.

Yes, at my age I have had a few preps for colonoscopy. Unpleasant - yes; but certainly tolerable.
Jon, if the plaintiff attorneys are starting to focus on bowel preps, maybe they are running out of things to do.

Date: Sun, 3 Feb 2013 12:28:59 -0500  From: Philippe R Koninckx and Anastasia Ussia 

This is a nice and important discussion not only clinically, but also on EBM. The limits of the evidence on MBP indeed are still unclear to me.
1. What is the power of the conclusion that there is no difference considering complications with a low incidence. What can we conclude when incidences are less than 1% (and thus requiring a RCT of some 6000. ) 2. More specifically what can we conclude for incidence or treatment of late bowel perforations as occurring after discoid resection for deep endometriosisMaybe because of age , but I remain reluctant to abandon practices which have been there for a long time, if I do not understand why they were erroneously introduced. Some were introduced because of rare ‘accidents’ .
Two examples out of many suggest prudence : it took us a decade to realise that chloramphenicol can cause very severe problems in 1/10000 only. After several decades of discussion it is still not that clear whether oral contraception is associated with cardiovascular problems besides trombosis, not to mention the ongoing debate on HRT.

Date: Tue, 5 Feb 2013 19:55:35 -0500   Elliot Greenberg  Assistant Clinical Professor, Tufts University School of Medicine

couldn’t agree with Dr Siedhoff more.There is no question that experience plays an important role in surgery. We have all seen studies that suggested treatments that are not borne out by experience and are later proven to be false due to poor study design. That being said, continuing practices such as routine bowel prep without good science to support it is a disservice to patients. Routine bowel prep is not a benign procedure. Although we don’t see it the next day, it is significantly traumatic both physically and emotionally to many patients.

For several years now we have abandoned the practice of mechanical bowel prep and have patients use a suppository or Fleets enema if we are concerned about solid stool in the rectum. We have had situations that required primary reanastamosis or repair and have not seen any increase breakdown of the repair, which is supported by the literature. None of our colorectal surgeons require or recommend full mechanical bowel prep for our patients when we are doing endometriosis surgery. It seems a shame to spend all that time providing minimally invasive surgery to reduce postoperative discomfort only to require maximally invasive preoperative prep which causes increased preoperative discomfort.

Elliot Greenberg MD, FACOG

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