EP0231356A1

EP0231356A1 - Low-sodium laxative and lavage formulation

Info

Publication number: EP0231356A1
Application number: EP86905052A
Authority: EP
Inventors: John S. Fordtran
Original assignee: Braintree Laboratories Inc
Current assignee: Braintree Laboratories Inc
Priority date: 1985-08-01
Filing date: 1986-07-31
Publication date: 1987-08-12
Also published as: JP2509594B2; WO1987000754A1; JPS63500523A; AU6196786A

Abstract

La solution ci-décrite est destinée au traitement de la constipation et au nettoyage du côlon. La solution utilisée pour le traitement de la constipation peut consister en un glycol de polyéthylène ou un glycol de polyéthylène et des ions sodium, des ions potassium, des ions chlorure et des ions bicarbonate. La solution utilisée pour nettoyer le côlon consiste en du glycol de polyéthylène, des ions sodium, des ions potassium, des ions chlorure et des ions bicarbonate; les ions sont présents dans la solution en quantités suffisantes pour empêcher une perte ou un gain net d'électrolytes du corps du patient. Un procédé de traitement de la constipation et un procédé de nettoyage du côlon sont également décrits.The solution described below is intended for the treatment of constipation and cleaning the colon. The solution used for the treatment of constipation may consist of a polyethylene glycol or a polyethylene glycol and sodium ions, potassium ions, chloride ions and bicarbonate ions. The solution used to cleanse the colon consists of polyethylene glycol, sodium ions, potassium ions, chloride ions and bicarbonate ions; enough ions are present in the solution to prevent a net loss or gain of electrolytes from the patient's body. A method of treating constipation and a method of cleaning the colon are also described.

Description

LOW-SODIUM LAXATIVE AND LAVAGE FORMULATION

Technical Field

This invention is in the field of medicine.and in particular relates to the treatment of constipa- tion and to colon cleansing necessary, for example, prior to diagnostic procedures or surgery.

Background Art

Constipation is a common and often serious problem for which numerous treatments have been developed. None of these, however, has proved to be entirely successful and many have serious limita¬ tions. For example, dietary manipulations (e.g., increasing the fiber content of the diet, removing foods thought to have a constipating effect) , laxatives and enemas are three commonly used ap¬ proaches to solving the problem. However, these approaches have important limitations, such as their ability to produce the desired effect; user accep¬ tance and compliance; and gas production (e.g., as a result of metabolism of fiber or carbohydrates, such as lactulose, by intestinal bacteria) . In addition, ingestion of laxatives can cause damage to the surface of the intestinal mucosa; ingestion of large quantities can cause loss of body water and electro- lytes (particularly potassium ions) and possibly kidney failure. Colon cleansing is very important prior to a number of diagnostic or surgical procedures. For example, thorough cleansing of the colon is said to be "essential to a successful diagnostic barium enema" and "one of the most important steps in the diagnosis of early colon cancer." Davis, G.R. and H.R. Smith, Gastrointestinal Radiology, : 173-176 (1983) . Colon cleansing is also necessary before colonscopy or colon surgery. A variety of methods can be used for colon cleansing; each, however, has important shortcomings and none is wholly successful. Dietary manipula¬ tion, laxatives and enemas are traditionally used for colon cleansing. For example, Thomas and co-workers have shown that clear liquids for 48 hours, in combination with laxatives and enemas, are relatively successful in producing a feces-free colon. Thomas, G. et al. , Gastroenterology, 82; 435-437 (1982) . These approaches are time consum- ing, inconvenient and unpleasant for the patient. Potentially harmful salt and water losses may occur when cathartics and enemas are used. Davis, G. et al. , Gastroenterology, 78; 9131-995 (1980).

Another approach to colon cleansing is intesti- nal lavage, in which a large volume of an electro¬ lyte solution is ingested, either by drinking or infusion by tube. The main component of the solu¬ tion has typically been sodium chloride. Its consumption results in volume-induced diarrhea and thus cleansing of the colon. This method is gener¬ ally faster than the traditional approaches, but there are questions about both the efficacy and the -3-

safety of lavage. A significant percentage of saline-based lavage solutions is absorbed by the user and a rapid increase in intravascular volume results. Consequently, this approach is unadvisable in individuals unable to excrete a water and salt load because of cardiac or renal disease. Thomas, G. et al. , Gastroenterology, 8_2: 435-437 (1982) ; Goldman, J. and M. Reichelderfer, Gastrointestianl Endoscopy, 28; 9-11 (1982) . Bacterial fermentation of mannitol, which is a component of some lavage solutions, may produce explosive gas mixtures in the colon.

In 1980, Davis and co-workers reported the development of a lavage solution described as associated with minimal water and electrolyte absorption or secretion. Davis, G.R. et al. , Gastroenterology, 78; 991-995 (1980) ; Davis G.R. and H.R. Smith, Gastrointestinal Radiology, 8_: 173-176 (1983) . The basic and critical ingredient in the solution is sodium sulfate, which is poorly ab¬ sorbed; sodium absorption is markedly reduced when sulfate, rather than chloride or bicarbonate, is the predominant intraluminal anion. In addition to the sodium sulfate, the solution described contains sodium chloride, potassium chloride, sodium bi¬ carbonate, polyethylene glycol or mannitol and water. The resulting solution has been shown to be effective in cleansing the gastrointestinal tract but it has disadvantages which interfere with its use. For example, patient acceptance can be a problem because of the solution's flavor, which is highly salty. There is a need for a method of treating constipation which is not only effective, but also acceptable. Although there are many methods which can be used for colon cleansing prior to diagnostic or surgical procedures, none is without limitations. Thus, there is also a need for a method of colon cleansing which is safe, more effective and better accepted by users than presently available methods.

Disclosure of the Invention The present invention relates to a formulation for the treatment of constipation and for colon cleansing, as well as a method for its use in treating constipation and producing cleansing of the colon. The formulation is comprised of polyethylene glycol (PEG) , which, in the treatment of constipa¬ tion, can be administered alone in an aqueous solution or can be administered in combination with electrolytes in an aqueous solution. In intestinal lavage, PEG is administered in combination with electrolytes in an aqueous solution. In treating constipation, the polyethylene glycol solution is administered in sufficient quantities to produce a soft stool. In effecting cleansing of the colon, the polyethylene glycol-electrolyte solution is administered orally or nasogastrically in sufficient quantities to produce rapid and thorough evacuation of the gastrointestinal tract. If electrolytes are present in the solution, they occur in amounts that will prevent a net loss of electrolytes from the body as a result of consumption of the solution. The sodium concentration of the formulation of the present invention is considerably lower than in the sodium-sulfate-based lavage solutions now in use. Therefore, the lavage solution does not have a salty taste, as do the sodium-sulfate-based solutions. There are at least three important advantages to the use of PEG in the treatment of constipation. First, PEG is poorly absorbed or not absorbed at all in the gastrointestinal tract; in addition, it is not fermented by coIonic bacteria; therefore, PEG is not metabolized to products which can be absorbed or to gaseous products (such as hydrogen gas) which can cause patient discomfort (e.g., flatulence). In contrast, mannitol, which is also poorly absorbed, is fermentable by colonic bacteria and some of the fermentation products are absorbed in the colon; some of the fermentation products are gases. Second, when PEG is used in the treatment of con¬ stipation, stool weight remains elevated, even after PEG is consumed for three consecutive days; this is apparently due to the fact that because PEG is not metabolized by colonic bacteria, there is no adap¬ tive increase in the bacterial population with time. Third, consumption of PEG does not adversely affect the intestinal mucosa. Similarly, the fact that PEG is poorly absorbed or not absorbed at all in the gastrointestinal tract and is not fermented by colonic bacteria is advan¬ tageous in its use as a lavage solution for colon cleansing. As a result, there is no rapid increase in intravascular volume and no production of potentially explosive gases. Brief Description of the Drawing

The figure represents graphically the secretion and absorption of water and electrolytes after lavage with a balanced electrolyte solution (BES) , Golytely (GL) or the low sodium-PEG lavage solution of the present invention.

Detailed Description of the Invention

PEG in sufficient quantity in an aqueous solution to produce a soft stool can be used for treatment of constipation. Similarly, PEG in an aqueous solution can be administered orally or nasogastrically to effectuate rapid evacuation of the gastrointestinal tract. In the treatment of constipation, PEG can be administered alone or in combination with electrolytes. In effecting colon cleansing, PEG is administered in combination with electrolytes. In the PEG-electrolyte formulations, electrolytes are present in sufficient quantities to prevent a net electrolyte loss_, from the body. Electrolytes included in a solution of the present invention include sodium ions, potassium ions chloride ions, and bicarbonate ions, alone or in any desired combination. The PEG solution of the PEG- electrolyte solution can also contain flavoring material, such as Crystal Light , aspartame or other suitable flavoring agent.

The sodium concentration of the formulation of this invention is less than 100 milliequivalents per liter, and will generally be less than 75 milliequiva- lents per liter. In one preferred embodiment, the sodium concentration is about 65 milliequivalents per liter. This is much lower than the sodium concentration of the two sodium-sulfate based lavage solutions (Golytely and Colyte) currently available. (The sodium concentration of these two solutions is 125 milliequivalents per liter.) Because of its low sodium content, the solution of the present inven¬ tion does not have the highly salty taste complained of by users of presently available solutions.

According to the present invention, from about 75 to about 300 grams of PEG is present in a liter of solution. In one preferred embodiment, PEG 3350 is present in water at a concentration of about 105 grams (gm) per liter of solution. Each of the ions is present in a concentration of from about 2 to about 100 milliequivalents. In one preferred embodiment, sodium ions are present in a concentra¬ tion of about 65 milliequivalents per liter, chloride in a concentration of about 53 milli¬ equivalents per liter, bicarbonate ions in a concen- tration of about 17 meq per liter and potassium ions in a concentration of about 5 meq per liter. .

In another preferred embodiment, PEG 3350 is present in water at a concentration of about 120 gm per liter of solution. In another embodiment, about 120 gm of PEG 3350 is present per liter of solution along with sodium ions, potassium ions, chloride ions and bicarbonate ions. Each of the ions is present in a concentration of from about 5.0 milli¬ equivalents per liter to about 50 milliequivalents per liter; in a preferred embodiment, they are present in a liter of solution in the following concentrations: sodium ions, 46.6 milliequivalents; potassium ions, 9.0 milliequivalents; chloride ions, 35.0 milliequivalents; and bicarbonate ions, 20.9 milliequivalents.

The PEG solution of this invention is made by combining PEG 3350 with sufficient water to make a liter of solution. For example, in one embodiment, about 105gm of PEG 3350 is combined with sufficient water to make a liter of solution. In another embodiment, about 120 gm. of PEG 3350 is combined with sufficient water to make a liter of solution. If the PEG solution is to contain electrolytes as well, sources of the ions listed above (in dry form) are combined with PEG and mixed in a standard blender. The PEG-electrolyte solution is made by combining the PEG-electrolyte mixture with enough water to make a liter of solution.

In the treatment of constipation, individuals consume from about 50 to about 500 milliliters of either the PEG solution or the PEG-electrolyte solution, generally once a day or with meals. In one preferred embodiment, individuals consume about 250 milliliters of either the PEG solution or the PEG-electrolyte solution. In particular, they consume about 250 milliliters of either the PEG solution having about 105 gm. of PEG 3350 in suffi¬ cient water to make a liter of solution or the PEG-electrolyte solution having the same PEG 3350 concentration. If the solution also has electro¬ lytes, each is present in a concentration of from about 2 milliequivalents to about 100 milliequiva¬ lents per liter. Consumption of this quantity should result in an increase in stool weight of from about 100 gm to about 300 gm. per day and thus relieve constipation.

Administration of this quantity of PEG will cause an increase in stool water, as well as produce a soft stool. These two changes will contribute to a solution to the problem of constipation. In addition, PEG is not fermented by colonic bacteria and there is no production of gases (such as hydro- gen gas) which can cause flatus and associated discomfort in the user. There will be no signifi¬ cant loss of electrolytes from the body particularly when the electrolytes listed above are included in the PEG solution. For colon cleansing, individuals are generally lavaged with the PEG-electrolyte solution at a rate of about 20-30 milliliters per minute (1.2-1.8 liters per hour) . That is, the solution is adminis¬ tered orally or nasogastrically at this rate. In the PEG-electrolyte solution, the electrolytes are each present in a concentration of from about 2 milliequivalents to about 100 milliequivalents per liter. The total volume of solution necessary to produce colon cleansing varies from individual to individual; it generally will be from 3 to 4 liters, although some individuals will require smaller or larger quantities. In one embodiment, individuals are lavaged at the rate of 20 milliliters per minute with the PEG-electrolyte solution having about 120 gm. of PEG 3350, 1.68 grams sodium bicarbonate, 0.74 gm potassium chloride and 1.46 gm sodium chloride in sufficient water to make a liter of solution. In a second embodiment, they are lavaged with PEG-electro- lyte solution have the following components, each expressed as grams/liter of solution: PEG 3350, 105; sodium chloride, 2.80; sodium bicarbonate, 1.43 and potassium chloride, 0.37. This invention is further illustrated by the examples given below which are not to be seen as limiting in any way.

Example 1 Osmolality of Polyethylene Glycol Solu¬ tions

Polyethylene glycol (PEG) was dissolved in water in the amounts shown in Table 1. The osmolality of each solution was measured by freezing point depression. As shown in Table 1, as the concentration of PEG is increased, the osmolality increases disproportionately. For example, a solution containing 60gm PEG per liter is osmoti- cally equivalent to 40mOsm/ g. When the concentra¬ tion of PEG is doubled, to 120gm per liter of solution, the osmolality increases almost fourfold (to 156MOsm/Kg.) .

Table 1 Osmolality of PEG Solutions

PEG Concentration Osmolality (gm/liter) (mOsm/Kg.)

50 35 60 40

100 103

120 156

150 255

200 475 Example 2 Effect of PEG Ingestion on Stool Weight and Comparison with the Effect of Mannitol Ingestion on Stool Weight

Four subjects consumed mannitol in an aqueous solution and eight subjects consumed PEG in an aqueous solution for three consecutive days. The amount of mannitol or PEG consumed by each subject is shown in Table 2; the PEG solutions consumed by the eight subjects contained approximately 60 grams of PEG per liter. Prior to treatment, the stool weight (gm./day) for each subject was determined. Stool weight was also determined for each of the three days during which subjects consumed either mannitol or PEG. These weights are also shown in ^'Table 2.

TABLE 2

Quantity of Mannitol or PEG Consumed; Stool Weights

Subjects Consuming Amount Consumed Stool Weight Mannitol (gms) (mMoles) (gm. /:24hr.) No Treatment Treatment Days

______ _____ 3

1 17 96 175 380 424 271 2 17 96 133 356 417 179

3 17 96 147 515 494 146

4 26 144 195 656 515 205

MEAN±SEM¹ 162 477 462 200

±14 +69 25 26

Subjects Consuming PEG

1 72 - 21 129 290 398 861

2 72 21 116 625 566 507

3 72 21 195 563 692 531

4 72 21 102 641 183 510

5 108 32 62 930 866 695

6 108 32 147 1442 1006 1056

7 144 43 175 1096 1274 942

8 144 43 ^' 133 1638 1097 1858

MEAN±SEM¹ 132 903 760 870

+15 ±114 ±131 ±154

^"Standard error of the mean

Stool weights were greater than the pretreat- ment stool weights on day 1 and day 2 for those consuming mannitol; on day 3, however, for all four subjects, the stool weight was less than on the two previous days and in three of the four cases, approached the pretreatment weight. In contrast, stool weight remained greater on each^' of the three days for those consuming the PEG solution. This difference appears to be due to the fact that colonic bacteria can ferment the mannitol, but not the PEG. When a mannitol solution is consumed, there apparently is an adaptive increase in colonic bacteria during day one and day two, with the result that almost all of the mannitol is fermented and the laxative effect prevented after the initial period of administration. None of the subjects consuming PEG complained of excessive flatus; this was a troublesome symptom in those ingesting mannitol. This is also probably the result of the nonferment- able nature of PEG.

Example 3 Use of Low Sodium-PEG Solution to

Produce Cleansing of the Colon

A normal subject was lavaged at the rate of 30 milliliters per minute (1.8 liters per hour) with a solution having the following composition: PEG concentration 120 g/L of solution*

Measured Sodium cone 46.6 mEq/L of solution

Measured potassium cone 9.0 mEq/L of solution

Measured chloride cone 35.0 mEq/L of solution

Measured bicarbonate cone 20.9 mEq/L of solution

Osmolality 293 Os/Kg of water

* Equivalent to 156 mOsm/Kg when present as the only solute.

The solution had been made by combining 120 gm. PEG; 1.68 gm. sodium bicarbonate (NaHCO^) ; 0.74 gm. potassium chloride (KCl) ; and 1.46 gm. sodium chloride (NaCl) and adding sufficient water to make one liter of solution.

Results of colon cleansing with this solution were compared with results produced using a balanced electrolyte solution (BES) and Golytely (GL) . They are best described with reference to the figure. Golytely is the tradename for the lavage solution, described by Davis and co-workers, which is based primarily on sodium sulfate (see above) . The results with the low sodium-PEG solution of the present invention are indicated by an X, plotted in between results for the other two solutions.

These results show that use of the low sodium- PEG solution is associated with negligible body gains or losses of water, sodium, chloride, bi¬ carbonate and potassium. Example 4 Use of Low-Sodium-EPG Solution in a Perfusion Study

Study Design

After an overnight fast, subjects swallowed a single-lumen, mercury-weighted polyvinyl tube, the tip of which was in the stomach. A solution having the following components was used in the study:

Component Concentration

(gm/liter) PEG 3350 105.00

Sodium chloride 2.80

Sodium bicarbonate 1.43

Potassium chloride 0.37

This solution had the following concentrations of active ingredients:

Component Concentration

(meq/liter) Sodium 65

Chloride 53 Bicarbonate 17

Potassium 5

PEG-3350 was present in the solution in a concen¬ tration of 31.30 mmol/liter.

The solution was warmed to room temperature and infused into the stomach at a pump speed of 20 ml/minute or 30 ml/minute. The polyethylene present in the solution as an integral part of the formula¬ tion was also used as a nonabsorbable marker to assess water absorption or secretion (see below) . Twenty minutes after the start of the gastric infusion, the infusion of the solution was momentarily interrupted and 200 mg of sulfabromphthalein (BSP) was injected into the stomach through the polyvinyl tube. The infusion was then restarted at the same rate.

When all BSP has been eliminated> a steady state has been achieved. When such a state was achieved, a rectal tube was inserted into the rectum for collection of rectal effluent.

The perfusion was continued for two hours after steady state conditions were achieved. This two- hour period consisted of two 60 minute collection periods, during which PEG concentrations remained essentially the same, showing that a "steady state" existed. The collected samples of rectal effluent were then analyzed for PEG concentration, and electrolyte concentrations by standard methods. Net water and electrolyte movement were calculated by use of standard nonabsorbable marker equations (see below) . The results obtained in this study were compared with results obtained when a second group of subjects was infused under similar conditions with a sodium sulfate-based solution which also contained small amounts of PEG, chloride, bi¬ carbonate and potassium. This solution is com- mercially available under the name Golytely . Significance of differences between results was determined by group t-analysis. Data and Calculations

Results of the perfusion studies are shown in Table 3 and Table 4. In the tables, a(+) preceeding a value indicates net secretion and a(-) indicates net absorption

Table 3 Perfusion with Low-Sodium- -PEG Solution

Infusion

Subject Rate Water Ions

Sodium Potassium Chloride Bicarbonate

(ml/min) (ml/hr) (meq/hr) (meq/hr) (meq/hr) (meq/hr)

1 19.1 -223.0 -15.8 -1.1 -13.0 -0.2

2 20.3 -28.0 3.1 -0.3 8.0 1.4

3 20.1 -66.0 5.2 -0.6 10.4 0.2

4 21.4 -7.0 5.2 0.1 10.4 2.4

5 20.7 164.0 31.6 0.3 32.7 5.7

6 21.2 -93.0 -7.1 -1.8 -2.7 -1.6

7 20.8 -65.0 10.1 -0.6 23.4 0.8

8 30.9 130.0 27.6 0.9 36.0 6.4

9 29.8 -62.0 5.6 0.1 10.7 5.2

10 29.8 -228.0 -23.9 0.4 -12.0 -8.2

11 29.5 -107.0 -0.5 -0.8 10.7 -2.5

12 29.8 10.0 7.2 0.9 16.7 5.4

13 30.1 36.0 10.2 1.6 28.7 -1.5

14 30.1 -24.0 10.3 2.0 22.7 -6.0 mean -40.2 4.9 0.07 13.1 0.5

Table 4 Perfusion with Sodium-Sulfate-Based Solution

Infusion

Subject Rate Water Ions

Sodium Potassium Chloride Bicarbonate

(ml/min) ( l/hr) (meq/hr) (meq/hr) (meq/hr) (meq/hr)

1 . 30.8 -77.0 -4.1 -2.7 7.6 -15.2

2 29.0 -198.0 -27.4 -5.5 -5.8 -7.3 CO

3 31.0 -33.0 -1.0 -2.4 -4.4 -6.7

4 29.2 -116.0 -18.8 -4.8 -14.7 -7.3

5 28.1 -7.0 -10.9 -2.9 -0.7 -8.3

6 30.5 163.0 24.9 7.4 34.3 -7.6

7 26.8 -30.0 -1.8 -2.2 1.4 -5.6

8 29.7 -47.0 -4.7 -1.7 3.6 -8.5

9 30.2 16.0 13.7 -0.5 22.6 -6.3

10 27.8 -127.0 -3.6 -3.4 14.1 -9.6

11 26.7 -214.0 -25.8 -2.3 1.9 -13.3

12 24.9 -142.0 -13.1 -4.8 4.5 -8.9

13 23.6 41.0 2.9 -1.3 - -3.9

14 26.4 -116.0 -3.1 -0.5 22.6 -6.3 mean -63.4 -5.2 -2.0 6.7 -8.2

The results of significance testing are shown in Table 5

Table 5 t Test for Comparing Independent Means measurement s 2 e P

Water 11111 0.6 > 0.1

Sodium 145 2.2 0.05

Potassium 5.. 4 2.2 -0.05

Chloride 207 1.2 >0.1

Bicarbonate 363 5.4 ^0.001

* n = 27

Where s2" is the pooled estimate of common variance, Of the parameters measured, sodium, potassium and bicarbonate showed significnat differences between the two formulations. To determine whether this difference represents an improvement, the following null hypothesis was tested: there is no difference between results obtained when the low- sodium-PEG solution was given and zero absorption/ secretion. Results of this analysis are shown in Table 6.

Table 6 t Test measurement s ^fc13 P

Water 110 1.4 > 0.1

Sodium 9.7 1.9 > 0.05

Po assium 1.1 0.2 >0.1

Chloride 15.1 3.2 4.0.01

Bicarbonate 4.4 0.4 >0.1

Where s is the sample standard deviation. These results indicate that no significant difference was observed between the data obtained when the low-sodium-PEG solution was administered and zero net absorption/secretion for all of the parameters measured, except for chloride, which was not significantly different from the sodium sulfate- based solution (Golytely) . For sodium, potassium and bicarbonate, there is a substantial improvement over results obtained when the sodium sulfate-based solution was administered.

Industrial Utility

This invention has industrial application in the treatment of constipation, which is a common and often serious medical problem, and in cleansing of the colon, which is necessary, for example, prior to diagnostic and surgical procedures.

Equivalents

Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific materials and components described specifically herein. Such equivalents are intended to be encom¬ passed in the scope of the following claims.

Claims

1. A solution comprising, per liter, the following components: a. from about 75 grams to about 300 grams of polyethlyene glycol; b. from about 2 milliequivalents to about 100 milliequivalents of sodium ions; c. from about 2 milliequivalents to about 100 milliequivalents of potassium ions; d. from about 2 milliequivalents to about 100 milliequivalents of chloride ions; and e. from about 2 milliequivalents to about 100 milliequivalents of bicarbonate ions.

2. A solution for treatment of constipation comprising an aqueous solution of polyethylene glycol, said polyethylene glycol being present in an effective constipation-relieving quantity.

3. A solution of Claim 2 additionally containing: a. sodium ions; b. potassium ions; c. chloride ions; and d. bicarbonate ions, in sufficient quantities to prevent a net loss of electrolytes in the person to whom the solution is administered.

4. A solution of Claim 2 in which polyethylene glycol 3350 is present in a concentration of from about 75 grams to about 300 grams per liter.

5. A solution of Claim 4 additionally containing from about 2 to about 100 milliequivalents of each of the following ions: a. sodium ions; b. potassium ions; c. chloride ions and d. bicarbonate ions.

6. A solution for treatment of constipation, said solution containing per liter, the following components: a. about 105 grams of polyethylene glycol 3350; b. from about 2 milliequivalents to about 100 milliequivalents of sodium ions; c. from about 2 milliequivalents to about 100 milliequivalents of potassium ions; d. from about 2 milliequi alents to about 100 milliequivalents of chloride ions; and e. from about 2 milliequivalents to about 100 milliequivalents of bicarbonate ions.

7. A solution for use in the treatment of constipation in a person, said sodium being comprised of polyethylene glycol 3350 in sufficient quantities to produce softening of the stools produced by the person to whom the solution is administered.

8. A solution of Claim 7, additionally comprising sufficient quantites of: a. sodium ions: b. potassium ions: c. chloride ions; and d. bicarbonate ions, to prevent a net loss of electrolytes from the body of the person to whom the solution is • administered.

9. A method of treating constipation, comprising administering to a person sufficient quantities of a solution of polyethylene glycol to cause softening of the stools produced by the person to whom the solution is administered.

10. A method of Claim 9 wherein the solution additionally contains sufficient quantities of: a. sodium ions; b. potassium ions; c. chloride ions; and d. bicarbonate ions to prevent a net loss of electrolytes from the body of the person to whom the solution is administered.

11. A method of treating constipation comprising administering to a person sufficient quantities of a solution to produce a laxative effect in the person, the solution comprising poly- ethylene glycol 3350.

12^'. A method of Claim 11 in which from about 50 to 500 milliliters of the solution is adminis¬ tered.

13. A method of Claim 12 in which a liter of the solution additionally contains from about 2 to about 100 milliequivalents of each of the following: a. sodium ions; b. potassium ions; c. chloride ions; and d. bicarbonate ions.

14. A method of treating constipation, comprising administering to a person sufficient quantities of a solution comprised of: a. polyethylene glycol 3350; b. sodium ions; c. potassium ions; d. chloride ions; and e. bicarbonate ions, to produce a laxative effect in the person, the concentrations of the ions in said solution sufficient to prevent a net loss of the ions from the body of the person to whom the solu¬ tion is administered.

15. A solution which, administered orally or nasogastrically to a person, causes evacuation of the gastrointestinal tract, the solution being comprised of: a. polyethylene glycol 3350; b. sodium ions; c. potassium ions; d. chloride ions; and e. bicarbonate ions.

16. A solution which will cause rapid cleansing of the gastrointestinal tract when administered orally or nasogastrically in sufficient quanti¬ ties to a person, a liter of the solution comprising: a. from about 75 grams to about 300 grams of polyethylene glycol; b. from about 40 milliequivalents to about 70 milliequivalents of sodium ions; c. from about 2 milliequivalents to about 15 milliequivalents of potas¬ sium ions; d. from about 30 milliequivalents to about 60 milliequivalents of chloride ions; and e. from about 10 milliequivalents to about 25 milliequivalents of bi¬ carbonate ions.

17. A solution for causing evacuation of the colon, a liter of the solution being comprised of the following components: a. about 120 grams of polyethylene glycol 3350; b. about 46 milliequivalents of sodium ions. c. about 9 milliequivalents of potassium ions; d. about 35 milliequivalents of chloride ions; and e. about 21 milliequivalents of bi¬ carbonate ions.

18. A solution for causing evacuation of the colon, a liter of the solution being comprised of the following components: a. about 105 grams of polyethylene glycol 3350; b. about 65 milliequivalents of sodium ions. c. about 5 milliequivalents of potassium ions; d. about 53 milliequivalents of chloride ions; and e. about 17 milliequivalents of bi¬ carbonate ions.

19. A low-sodium lavage solution which, when administered to a person, will cause cleansing of the gastrointestinal tract, the solution having the following components: polyethylene glycol 3350, sodium ions, bicarbonate ions, these components being present in the solution in sufficient quantities to cause cleansing of the gastrointestinal tract.

20. A solution of Claim 19, a liter of the solution comprising: a. about 105 grams of polyethylene glycol 3350; b. about 65 milliequivalents of sodium ions; c. about 5 milliequivalents of potassium ions; d. about 53 milliequivalents of chloride ions; and e. about 17 milliequivalents of bi- carbonate ions.

21. A lavage solution having no added sulfate, which, when administered orally or nasogastri¬ cally in sufficient quantities to a person, causes cleansing of the gastrointestinal tract, the solution being comprised of polyethylene glycol 3350, sodium ions, potassium ions, chloride ions and bicarbonate ions, the con¬ centrations of the ions being sufficient to prevent net absorption or excretion of those ions in the gastrointestinal tract.

22. In a solution, comprising electrolytes and polytheylene glycol 3350, which is administered to a person to cause cleansing of the gastro¬ intestinal tract, the improvement comprising a low sodium concentration and the absence of added sulfate.

23. A method of causing evacuation of the colon, comprising the administration of sufficient quantities of a solution to cause the evacu- ation, each liter of the solution comprising: a. from about 75 grams to about 300 grams of polyethylene glycol; b. from about 40 milliequivalents to about 70 milliequivalents of sodium ions; c. from about 2 milliequivalents to about 15 milliequivalents of potas¬ sium ions; d. from about 30 milliequivalents to about 60 milliequivalents of chloride ions; and e. from about 10 milliequivalents to about 25 milliequivalents of bi¬ carbonate ions.

24. A method of cleansing the colon, comprising the administration of sufficient quantities of a solution to cause the cleansing, a liter of the solution comprising: a. about 105 grams of polyethylene glycol; b. about 65 milliequivalents of sodium ions; c. about 5 milliequivalents of potassium ions; d. about 53 milliequivalents of chloride ions; and e. about 17 milliequivalents of bi- carbonate ions.

25. In a method of causing the evacuation of the colon by oral or nasogastric administration of a lavage solution comprising electrolytes and polythylene glycol, the improvement comprising a lavage solution having a low sodium concentra¬ tion and the absence of added sulfate.