Being confused about the difference between preps, I did some googling and this came up:
Miralax (PEG 3350) vs. Golytely as Bowel Preparation for Screening Colonoscopy
A major limitation to the widespread acceptance of colonoscopy as a procedure to screen for colorectal cancer is the laxative preparation. Phosphate-based preps (e.g. Fleets Phosphosoda) are now used on a limited basis because of their known association with renal injury. Polyethylene glycol (PEG) mixed with a balanced electrolyte solution (e.g. Golytely) has been used for over two decades for colon cleansing. The mixture is not very palatable due to the electrolyte additives which include sodium sulfate.
To overcome the limitation of existing preps, gastroenterologists and colorectal surgeons worldwide have been using PEG powder alone (same quantity as found in Golytely prep) not mixed with electrolytes (Glycolax or Miralax) and dissolving this into 64 ounces of Gatorade. Conservatively, we estimate that 25% of colonoscopies in the US are being done with this prep. Anecdotally there have been reports (case series) that it is far more palatable and the prep is equally efficacious. The active ingredient, PEG, is not changed and therefore this is not surprising.
My husband's doctor uses Miralax, which they say can be mixed with Crystal Light lemon flavor (the food coloring is the issue).
Here is further info:
http://www.cancer.gov/clinicaltrials/se ... ofessional
Background Colonoscopy is the standard method for luminal evaluation of the colon. Bowel cleansing prior to colonoscopy is critical to the endoscopist obtaining optimal visualization during the procedure and therefore plays an integral role in safety, efficacy and diagnostic accuracy of the procedure. The bowel cleansing portion of the procedure is often the most lamented aspect of the colonoscopy experience. This is often driven by the large volume of liquid required to be consumed, in addition to the poor palatability of some colon cleansing regimens. Cleansing methods are variable, and often times high volume solutions are time consuming, inconvenient and uncomfortable, leading to poor patient compliance. This translates into decreased effectiveness of the colonoscopy exam and often higher costs due to the need for repeat examination. Additionally, it is unknown how much the feared discomfort of the bowel preparation experience dissuades patients from pursuing a screening colonoscopy for colon cancer.
An ideal bowel preparation would reliably cleanse the colon in a rapid fashion, would not alter the colonic mucosa, result in an acceptable amount of patient discomfort, would not cause significant shifts in electrolytes and would be inexpensive. To date, no bowel regimen meets all of these criteria.
One of the standard bowel preparation regimens is polyethylene glycol (PEG, Golytely) lavage solution which entails consuming 4 L of water mixed with a powder packet that contains the main ingredient (255g polyethylene glycol 3350) along with electrolytes (22.74 g anhydrous sodium sulfate, 6.74 g sodium bicarbonate, 5.86 g sodium chloride, 2.97 g potassium chloride). This is a non-absorbable, iso-osmotic solution which has a mildly salty taste that induces a diarrhea that rapidly cleanses the bowel, usually within 4 hours. This solution was first introduced in the 1980's and is currently the most widely used bowel cleansing regimen (1). It has proven safety and efficacy but due to its high volume, it is often difficult for patients to tolerate (2-7). It has been estimated that at least 5-15% of patients do not complete the preparation due to the large volume and/or poor palatability (8, 9). The literature also confirms that patients prefer lower volume solutions for comfort and tolerability (7, 10).
Oral sodium phosphate solutions (e.g. Fleets PhosphoSoda®) were equally efficacious and shown to be better tolerated low volume alternatives to PEG (11). They were FDA approved for bowel cleansing and were been used extensively in select patients prior to colonoscopy until recently. However, on December 11, 2008, the FDA issued a statement concluding that the use of oral sodium phosphate preparations poses a risk of serious adverse events, notably acute phosphate nephropathy- a type of acute kidney injury- in select patients (patients over age 55, baseline kidney disease, on diuretics, angiotensin converting enzyme [ACE] inhibitors, NSAIDs or angiotensin-receptor blockers [ARBs] etc) (12-14). As a result, the FDA has required that manufacturers of oral sodium phosphate bowel preparations add a Boxed Warning to their labels of these products. Subsequently, these manufacturers have voluntarily removed their products from retail sale. There have been over 20 randomized controlled trials in the literature searching for the "ideal" bowel preparation (11). With the removal of oral sodium phosphate preparations from the market, the search for a better tolerated bowel cleansing regimen continues.
Miralax (PEG 3350), polyethylene glycol powder alone without electrolytes is FDA approved for constipation. It is mixed in 8-12 ounces of any beverage and can be used daily. Because it lacks taste (no electrolytes) it has been used as a bowel cleanser for colonoscopy. Generally, 255 g of Miralax is combined with 64 oz of Gatorade for bowel cleansing prior to colonoscopy. While not FDA approved for this indication, it has been widely used and is an accepted alternative to Golytely in numerous endoscopy centers across the country.
PEG 3350's safety and efficacy has been documented in multiple studies on children undergoing colonoscopy (15, 16). A recent single arm feasibility study described in a letter to the editor in the American Journal of Gastroenterology 2008 found the use of Miralax (PEG 3350) as colonoscopic preparation to be tolerable and safe in adults (17). Moreover the study reported high compliance. It included 29 patients who underwent screening colonoscopy with PEG 3350 in 64 oz of Gatorade® (The Gatorade Company, Chicago, IL). A "good prep" was described in 97% of cases; patient rated tolerance was good in 86%. Insomnia was the most common adverse effect. Of note, 18 patients had prior 4L PEG bowel cleansing experiences- of these, 50% reported PEG 3350 was better tolerated. Beyond this data, these investigators at a community center (Urbana, IL) have a 3 year exclusive experience with PEG 3350 as their colon preparation; they report anecdotally better patient tolerance and compliance over prior preparations. The inclusion of Gatorade® is to reduce the potential for electrolyte disturbances.
Note the last sentence, "The inclusion of Gatorade® is to reduce the potential for electrolyte disturbances". Guess my husband's doctor is not too worried about electrolyte disturbances, because they recommend Crystal Lite just as a flavoring.
I also found this:
http://www.druglib.com/abstract/hj/hjel ... 10400.html
BACKGROUND & AIMS: Successful colonoscopies require good bowel preparations-poor bowel preparations can increase medical costs, rates of missed lesions, and procedure duration. The combination of polyethylene glycol (PEG) 3350 without electrolytes (MiraLAX; Schering-Plough Healthcare Products, Inc, Kenilworth, NJ) and 64 oz of Gatorade (PepsiCo, Inc, Purchase, NY) has gained popularity as a bowel preparation regimen. However, the efficacy and tolerability of this approach has not been compared with standard bowel preparations in clinical trials. We compared split-dose (PEG) 3350 with electrolytes (GoLytely; Braintree Laboratories, Inc, Braintree, MA) with split-dose MiraLAX alone and in combination with pretreatment medications (bisacodyl or lubiprostone) to determine the efficacy and patient tolerability of MiraLAX as an agent for bowel preparation. METHODS: We performed a prospective, randomized, blinded, controlled trial at a tertiary care center. Patients (n=403) were randomly assigned to groups given GoLytely, MiraLAX, MiraLAX with bisacodyl (10 mg), or MiraLAX with lubiprostone (24 mug). MiraLAX was combined with 64 oz of Gatorade. All patients were surveyed regarding preparation satisfaction and tolerability. The Ottawa bowel preparation scale was used to grade colon cleanliness. RESULTS: GoLytely was more effective at bowel cleansing (average Ottawa score, 5.1) than MiraLAX alone (average Ottawa score, 6.9) or in combination with lubiprostone (average Ottawa score, 6., or bisacodyl (average Ottawa score, 6.3) (P<.001). MiraLAX was associated with a trend toward longer procedure duration (P=.096). Groups given MiraLAX rated the overall experience as more satisfactory than those given GoLytely (P<.001). There were no differences between polyp detection rates (P=.346) or adverse events (P=.823). CONCLUSIONS: Split-dose MiraLAX in 64 oz of Gatorade is not as effective as 4 L split-dose GoLytely in bowel cleansing for screening colonoscopies.
It indicates that GoLytely was more effective as a prep, although MiraLax was given a better satisfaction rating by those using the prep. But most interesting to me is that "There were no differences between polyp detection rates".
I wonder, just how "cleaned out" does someone need to be, and if both products result in a satisfactory "cleaning", even if one was [quote] "more effective", is the difference between the two of a degree that even matters? Especially since there ended up being no difference between polyp detection rates, which is often the reason for doing the colonoscopy.