Patent Publication Number: US-2022233759-A1

Title: Spool valve for body cavity irrigation devices

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/882,246, filed Aug. 2, 2019, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure is directed to flow control within body cavity irrigation devices, and more particularly to a spool valve and a method of using the spool valve in body cavity irrigation devices. 
     More particularly, the disclosure provides a spool valve for use in cavity irrigation devices such as for use in an electromechanical rectal irrigation (RI) or stoma irrigation (SI) device, which may alternatively be referred to as a trans-anal irrigation (TAI) device, wherein the device has a base unit and a controller, such as is disclosed in International Patent Application No. PCT/US17/41205, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     Many individuals suffering spinal cord injury (SCI) and other medical conditions (e.g., cauda equina syndrome, multiple sclerosis (MS), spina bifida (SB), and chronic constipation) may need to avail themselves of bowel management treatments, in many cases along with a bladder management program. For SCI users, the issues of independence, dexterity, and ease of use are important needs that must be addressed by a bowel management program. Users can avail themselves of various solutions such as pharmacological (laxatives/suppository), digital stimulation, diet control and others, with the aim of having a regular bowel management routine without constipation or fecal incontinence. 
     TAI provides another option for bowel management. RI is the delivery of irrigating liquid into the colon to flush the body&#39;s system of stool and create pseudo-continence for the end user. Devices currently on the market allow the user to utilize a product over the toilet, in a commode/shower chair or in a bed to introduce water into the bowel through a rectal catheter. The user will introduce an amount of water into the bowel (typically 500-700 mL) in order to flush out stool located in the bowel passage. It is common for the user to introduce the water, wait for a period of time and allow gravity to flush the water and stool out of the body. The rectal catheter may have an inflatable/deflatable balloon to assist in retention of the catheter during water introduction. The balloon is typically inflated by a fluid such as air or water. Thus, there may be various tubing sets specifically configured for each type of use. 
     The typical RI device has an irrigation liquid reservoir and a pump base unit which contains a pump for pumping water from the reservoir through suitable tubing to the catheter. RI devices may use water to inflate a balloon of a rectal catheter. The devices may have a single-lumen tubing from a reservoir into a controller, and dual-lumen tubing from the controller to the catheter. One of the dual lumens may enable the rectal catheter balloon to be inflated with water and later deflated; while the second lumen may accommodates water transfer from the reservoir into the rectum. The device may provide that when the catheter balloon is deflated, a liquid communication channel is created so that water returning from the deflated balloon travels via the controller into the lumen toward the catheter, i.e. the water from the deflated balloon does not return to the water reservoir. 
     Thus, fluid tubing sets may contain two separate lumens, one for irrigation fluid or irrigant, and one for retention balloon inflation/deflation. With such a device, it is desirable that neither of the tubing lumens ever communicates with the other lumen during a RI procedure, so there is no fluid communication between the lumens. This may be accomplished, for example, as shown in the above-identified International Patent Application No. PCT/US17/41205, via use of a fluid control or hydraulic control circuit having a pump and at least three solenoid valves within a base. The solenoid valves are used to regulate the flow of water within the hydraulic control circuit and to ensure that the water in the separate tubing lumens remains independent. 
     Hence, by design, all tubing lumens are independent of each other, and there is no condition of the hydraulic control circuit that permits the lumens to communicate with one other. This ensures that water from the deflated catheter balloon only returns to the water reservoir, and not into the catheter or the lumens in communication with the catheter. Alternatively, the fluid tubing set may contain three separate lumens, one for irrigant, one for waste control valve actuation, and one for retention balloon inflation/deflation. Accordingly, devices may be configured for use with different catheters, whether having a dual of triple lumen catheter. 
     Devices also may be configured for use with catheters that are intended for different treatment modalities. For instance, when a balloon catheter is being used with a pump base unit and controller, the device needs to be primed, the retention balloon is inflated, the irrigant is instilled, and the retention balloon is deflated. By comparison, when a cone catheter is being used with a base unit and controller, the device needs to be primed and then the irrigant is instilled. Accordingly, there may be modalities that involve use of a cone catheter, or a balloon catheter, where the balloon catheter may be usable, for example, in a procedure conducted over a toilet or in a bed. The variety of tubing sets and modalities can present challenges for users. 
     The device disclosed in the above-identified International Patent Application No. PCT/US17/41205 includes example embodiments having a pump base unit and a controller, along with a plurality of solenoid valves to regulate the flow of water within the hydraulic control circuit. The first example embodiment in International Patent Application No. PCT/US17/41205 uses three separate solenoid valves to control fluid flow, to perform three stages in an RI procedure. The three solenoid valves include a reservoir flow director valve, a pump flow director valve, and a tubing flow director valve. However, use of at least three solenoid valves may have certain disadvantages. The solenoid valves may be constructed using metal material for the components. For example,  316 L stainless steel may be used to resist corrosion due to saline solution that may flow through the solenoid valves during testing, and water that may flow through the solenoid valves during use. Moreover, a device requiring three such stainless steel solenoid valves requires sufficient space to house the valves and adds expense and mass to the base unit. 
     SUMMARY 
     The present disclosure is directed to a body cavity irrigation device that includes a spool valve for use in controlling fluid flow within the irrigation device. The spool valve is used to regulate the flow of fluid depending on the stage of an irrigation procedure. The irrigation device may be used for RI or SI, generally referred to herein as TAI. The spool valve includes a valve body having an elongated bore and a plurality of ports that are spaced apart and in fluid communication with the bore. The ports also are in fluid communication with different components of the irrigation device. The spool valve also includes a spool that slides within the bore of the valve body. The spool includes a plurality of lands with seals, and a plurality of grooves, which are used to open and close the various ports of the spool valve in predetermined combinations that correspond to the position of the spool within the valve body and the desired stage of a procedure. In this manner, the spool valve is used within a hydraulic control circuit to control fluid flow within the passages of the device. The spool may be moved by an actuator, such as a linear actuator, motor or other device directly or through a drive mechanism that provides translational movement to the spool. The actuator is used to move the spool to different positions within the valve body to control fluid flow during the various stages of operation of a TAI procedure. 
     The spool valve may replace multiple solenoid valves, providing numerous advantages. For example, with respect to the first embodiment of the aforementioned International Patent Application No. PCT/US17/41205, incorporated by reference in its entirety herein, the spool valve advantageously requires a smaller footprint for the hydraulic control circuit within the pump base unit. Also, a single actuator may be used to move the spool, replacing for example three solenoids that otherwise may be used for actuation of three solenoid valves that would be needed to provide a similar hydraulic control circuit. 
     Additionally, the spool valve components may be molded or otherwise constructed of less expensive and lighter weight materials that do not corrode. For instance, polymer materials may be used to construct the spool and valve body and polymer or rubber materials may be used to construct the seals disposed between the spool and bore of the valve body. The corrosion resistant, lighter weight spool valve having a more compact arrangement advantageously may be used within a device that includes a pump base unit, an irrigation fluid reservoir, an electronic controller, and may be in fluid communication with conduits used in RI, SI, TAI or other irrigation devices, while providing an opportunity to use a single actuator to move the spool so as to control the fluid flow during the stages of a procedure. Such a device provides technical solutions to multiple technical problems by providing a device with a single actuator and that is more compact, lighter weight and more corrosion resistant. 
     It will be appreciated that the spool valve may be used with the controller to adjust the intended modality and to provide the proper operative procedures associated with a respective tubing set. The usability of a balloon catheter, for instance, to perform an RI procedure may involve the following steps: (1) prime the device (without the catheter attached); (2) attach the catheter and insert it safely inside the rectum; (3) inflate the retention balloon; (4) instill irrigation; (5) deflate the retention balloon; and (6) remove the catheter. The first two steps are conducted in preparation for the three stages set forth in steps 3-5. Those three stages are followed by removal of the catheter. The spool valve provides inlet/outlet ports for separate flow paths for communication with the tubing set. The spool valve effectively replaces the three solenoid valves discussed in the first example embodiment in PCT/US17/41205 and provides fluid control within the hydraulic control circuit useful in performing steps 3-5 of the aforementioned procedure. 
     In one aspect, the present disclosure provides a trans-anal irrigation device having a spool valve, the device including a pump, an irrigation fluid reservoir in fluid communication with the pump, a rectal catheter having a retention balloon and an irrigant passage through the rectal catheter, fluid tubing having at least two lumens, a first lumen providing fluid communication between the pump and the retention balloon, and a second lumen providing fluid communication between the pump and the irrigant passage. The device also includes a hydraulic control circuit including a spool valve having a spool that is movable by an actuator. The spool valve includes a valve body having an elongated bore and a plurality of ports spaced apart along and in fluid communication with the elongated bore. The spool further includes a plurality of lands separated by a plurality of grooves, and seals extending outward from the lands and sealingly engaging the elongated bore of the valve body. The plurality of ports and plurality of seals and grooves are arranged for selectively directing flow alternatively from the reservoir to the retention balloon, from the reservoir to the irrigant passage, or from the retention balloon to the reservoir, based on the position of the spool within the valve body. 
     In an additional aspect, the present disclosure provides a spool valve for use in a hydraulic control circuit of a trans-anal irrigation device, including a spool valve having a valve body including an elongated bore and a spool that is movable within the bore, an actuator that moves the spool relative to the bore, the spool valve further including a plurality of ports spaced apart along and in fluid communication with the bore. The spool further includes a plurality of lands and a plurality of seals extending radially outward from the lands and sealingly engaging the spool and the bore of the valve body, and the plurality of ports and plurality of seals and grooves are arranged for selectively directing flow through at least two passages in at least three alternative configurations based on the position of the spool within the bore of the spool valve. 
     In a further aspect, the present disclosure provides a method of establishing fluid paths through a spool valve in a hydraulic control circuit of a trans-anal irrigation device, wherein the spool valve includes a valve body having an elongated bore and a plurality of ports spaced apart along and in fluid communication with the bore, and a spool that is movable within the bore, and wherein the plurality of ports further includes a first port associated with a pump outlet, a second port associated with a reservoir, a third port associated with a pump inlet, a fourth port associated with a pump inlet, a fifth port associated with a retention balloon lumen, a sixth port associated with a pump outlet, and a seventh port associated with an irrigant lumen. The method includes the steps of moving the spool to a first position within the bore of the valve body wherein the second port is in fluid communication with the third port and the fifth port is in fluid communication with the sixth port, so as to establish fluid paths through the spool valve from the reservoir to the pump inlet and from the pump outlet to the retention balloon lumen; moving the spool to a second position within the bore of the valve body wherein the second port is in fluid communication with the third and fourth ports and the sixth port is in fluid communication with the seventh port, so as to establish fluid paths through the spool valve from the reservoir to the pump inlet and from the pump outlet to the irrigant lumen; and moving the spool to a third position within the bore of the valve body wherein the first port is in fluid communication with the second portion and the fourth port is in fluid communication with the fifth port, so as to establish fluid paths through the spool valve from the retention balloon lumen to the pump inlet and from the pump outlet to the reservoir. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In describing the preferred embodiments, reference is made to the accompanying drawing figures wherein like parts have like reference numerals, and wherein: 
         FIG. 1  is a simplified perspective view of an example body cavity irrigation device having a pump base unit, an irrigation fluid reservoir, an electronic controller, shown as optionally wireless, and a fluid tubing set. 
         FIG. 2  is a perspective diagrammatic view of the pump base unit with the cover and reservoir removed to expose the pump, motor, spool valve, batteries and electronic control circuit boards. 
         FIG. 3  is a perspective view of a spool valve of  FIG. 2 , showing a spool within a valve body, in a Stage 2 position to provide irrigant. 
         FIG. 4  is a perspective view of the spool of  FIG. 3 , showing the radially extending lands with seals. 
         FIG. 5  is a cross-sectional perspective view of the spool valve of  FIG. 2 , showing the spool in the bore of the valve body, in the Stage 2 position to provide irrigant. 
         FIG. 6  is a cross-sectional side view of the spool valve of  FIG. 2 , showing the spool in a Stage 1 position to provide retention balloon inflation. 
         FIG. 7  is a cross-sectional side view of the spool valve of  FIG. 2 , showing the spool in a Stage 2 position to provide irrigant. 
         FIG. 8  is a cross-sectional side view of the spool valve of  FIG. 2 , showing the spool in a Stage 3 position to provide balloon deflation. 
     
    
    
     It should be understood that the drawings are not to scale. While some mechanical details of the example spool valve for use in cavity irrigation devices, including other plan and section views of the particular components, have not been shown, such details are considered to be within the comprehension of those skilled in the art in light of the present disclosure. It also should be understood that the present disclosure and claims are not limited to the preferred embodiments illustrated. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present disclosure relates to components for use in an electromechanical body irrigation device  10 , such as a rectal irrigation (RI), stoma irrigation (SI) or trans-anal irrigation (TAI) device. A simplified view of such a system  10  is shown in  FIG. 1 . The system  10  may include a pump base unit  12 , an irrigation fluid reservoir  14 , a fluid tubing  16 , a tubing connector  18 , a disposable rectal catheter  20  and a wireless controller  22 . The controller  22  is shown in this example in the form of a separate controller that may communicate wirelessly with the pump base unit  12 . Alternatively, a controller for the system may be directly connected to or tethered by wired connection to the pump base unit  12 . Also, the fluid reservoir  14  may be removable from the pump base unit  12 , which in this example includes a connector  18  for establishing fluid communication with the proximal end of the fluid tubing  16 . 
     As shown in  FIG. 1 , the fluid tubing  16  is connected at its distal end to the catheter  20 . The catheter  20  has a retention balloon  24  that assists in sealingly holding the catheter  20  in the rectum. It will be appreciated that the retention balloon  24  may, for example, be attached to the exterior of the rectal catheter  20 . The fluid tubing  16  of this example may include a retention balloon tube or lumen and an irrigant tube or lumen, such as disclosed in more detail in the first example embodiment in International Patent Application No. PCT/US17/41205, which is incorporated herein by reference. 
     Turning now to the pump base unit  12 ,  FIG. 2  illustrates a generally hollow shell  100  which includes a floor  102  and a perimeter wall  104 . The wall  104  is configured to support the base of the reservoir  14  when the reservoir is installed on the pump base unit  12 . The wall  104  may have a handle  106  pivotably or otherwise connected to it. A user can grasp the handle  106  to carry the pump base unit  12 . The wall  104  also has an opening  108  through it for mounting a fitting on the end of the tubing  16 . The fitting allows connection of the tubing  16  and provides fluid communication between the pump and the fluid tubing  16  having a retention balloon lumen and an irrigant lumen. 
     Inside the shell  100  there is an electric motor  110 , a pump  112 , one example of which may be a one-way pump, and a spool valve  113  that is movably connected to an actuator  115 . It will be appreciated that the pump  112  includes at least one pump inlet and at least one pump outlet. The spool valve  113  effectively replaces the hydraulic control circuit that was provided by the three solenoid valves of first example embodiment in International Patent Application No. PCT/US17/41205, allowing the pump base unit  12  of the present disclosure to otherwise operate similarly. The three solenoid valves being replaced include a reservoir flow director valve, a pump flow director valve, and a tubing flow director valve. The solenoid valves were normally-open, three-way valves. 
     Also present within the shell  100  is a rechargeable battery pack  120  for powering the pump  112 , and internal tubing (not shown  FIG. 2  for ease of viewing the other components), which provides various fluid connections and paths between the spool valve  113 , the fluid reservoir  14 , the pump  112  and the tubing  16 . The fluid connections provided when using the spool valve  113  are in lieu of the connections of the internal tubing that are described in the fluid circuit diagrams shown for the first embodiment in International Patent Application No. PCT/US17/41205. Additionally located within the shell  100  are a power circuit board  122  and a controller printed circuit board  124 . A power button  126  may be located on the outside of the shell  100  to turn on and off the pump base unit  12 . 
     As shown in  FIGS. 2-8 , the spool valve  113  of the present example effectively replaces the aforementioned three solenoid valves in the device disclosed in FIGS. 1-14 of first example embodiment in International Patent Application No. PCT/US17/41205. It also will be appreciated that with respect to the additional embodiments in the aforementioned application that is incorporated by reference herein, use of the spool valve  113  could be accomplished to replace solenoid valves, so as to provide similar significant advantages. Accordingly, the spool valve  113  may provide a more compact, non-metallic, lighter weight, lower cost alternative to the use of at least three heavier and more expensive solenoid valves that may, for example, be constructed with stainless steel. 
     The spool valve  113  includes a valve body  150  having an elongated bore  152  is in fluid communication with a plurality ports  154   a - 154   g  that extend outward from the bore  152  and are spaced apart along the length of the bore  152 . The plurality of ports  154   a - 154   g  include a first port  154   a  associated with an outlet of the pump  112 , a second port  154   b  associated with the reservoir  14 , a third port  154   c  associated with an inlet of the pump  112 , a fourth port  154   d  associated with an inlet of the pump  112 , a fifth port  154   e  associated with a retention balloon lumen of the tubing  16 , a sixth port  154   f  associated with an outlet of the pump  112 , and a seventh port  154   g  associated with an irrigant lumen of the tubing  16 . The respective ports  154   a - 154   g  may be placed in fluid communication with different components of the irrigation device, as will be further described herein. 
     The spool valve  113  also includes a spool  156  that is slidably received by the bore  152  of the valve body  150 . The valve body  150  has a proximal end opening  150   a  to the full diameter of the bore  152 , which conveniently permits insertion of the spool  156  into the bore  152 . The valve body  150  also has a distal end opening  150   b  having a smaller diameter, which provides an integrated stop for movement of the spool  156  in the distal direction, while also avoiding increased pressure or vacuum within the valve body  150  when moving the spool  156 , which might otherwise restrict movement of the spool  156 . 
     The spool  156  includes a base  156   a  at its proximal end, which provides for mounting to an actuator  115 . The spool  156  also includes a plurality of lands, shown in this example as lands  158   a - 158   c.  Each land extends radially outward from a central stem  160  of the spool, and the lands  158   a - 158   c  are separated along the length of the stem  160  by a plurality of grooves  162   a,    162   b.  The lands  158   a - 158   c  include a plurality of circumferential seals  164   a - 164   h,  such as O-ring seals, which in this example are received by circumferential channels  166   a - 166   h  in the respective lands  158   a - 158   c.    
     The actuator  115 , which may for example be a linear actuator, a motor with a linkage or other suitable alternative configuration, so as to provide translational or sliding movement to the spool  156  relative to the bore  152  of the valve body  150 . The actuator  115  is controlled by the controller  22 . The controller  22  causes the actuator  115  to slidably move the spool  156  relative to the bore  152  of the valve body  150 . The multiple lands  158   a - 158   c  and seals  164   a - 164   h  extending over a significant length of the spool  156  provides for smooth sliding movement in the bore  152 . 
     Movement of the spool  156  fore or aft along the bore  152  establishes different flow paths through the valve body  150 . The seals  164   a - 164   h  and grooves  166   a - 166   h  effectively function to provide a hydraulic control circuit that opens and closes fluid pathways between ports  154   a - 154   g  of the valve body  150 . Thus, the spool valve  113  is used to movably arrange fluid pathways that control fluid flow in the body cavity irrigation device  10 . The spool  156  may be moved by the actuator  115  to different positions within the valve body  150  during operation of a TAI procedure. 
     The specific placement of the seals  164   a - 164   h  and grooves  162   a,    162   b  permit the single spool valve  113  to act as if it were three separate valves. For example, as shown in  FIG. 6 , the spool valve  113  is in a position that corresponds to Stage 1 of a procedure. In this position, three ports are effectively closed by being located between seals, namely, port  154   a  which is associated with the outlet of the pump  112  is closed by being located between seals  164   b  and  164   c,  while port  154   d  which is associated with the inlet of the pump  112  is closed by being located between seals  164   d  and  164   e,  and port  154   g  which is associated with the irrigant lumen is closed by being located between seals  164   f  and  164   g.  In this first position of the spool  156 , two separate flow paths are provided, namely, port  154   b  which is associated with the reservoir  14  and port  154   c  which is associated with the inlet of the pump  112  are in fluid communication via groove  162   a  due to the location of seals  164   c  and  164   d,  while port  154   e  which is associated with the retention balloon lumen and port  154   f  which is associated with the outlet of the pump  112  are in fluid communication via groove  162   b  due to the location of seals  164   e  and  164   f.  Thus, this configuration permits fluid to be pumped from the reservoir to the retention balloon lumen, so as to inflate the retention balloon  24 . 
     Referring to  FIG. 7 , the spool valve  113  has been moved and now is in a position that corresponds to Stage 2 of a procedure. In this position, two ports are effectively closed by being located between seals, namely, port  154   a  which is associated with the outlet of the pump  112  is closed by being located between seals  164   a  and  164   b,  while port  154   e  which is associated with the retention balloon lumen is closed by being located between seals  164   d  and  164   e.  In this second position of the spool  156 , two separate flow paths are provided, namely, port  154   b  which is associated with the reservoir  14  and ports  154   c  and  154   d  which are associated with the inlet of the pump  112  are in fluid communication via groove  162   a  due to the location of seals  164   c  and  164   d,  while port  154   f  which is associated with the outlet of the pump  112  and port  154   g  which is associated with the irrigant lumen are in fluid communication via groove  162   b  due to the location of seals  164   e  and  164   f.  Thus, this configuration permits fluid to be pumped from the reservoir to the irrigant lumen, so as to provide irrigation. 
     Turning to  FIG. 8 , the spool valve  113  has been moved again and now is in a position that corresponds to Stage 3 of a procedure. In this position, three ports are effectively closed by being located between seals, namely, port  154   c  which is associated with the inlet of the pump  112  is closed by being located between seals  164   d  and  164   e,  while port  154   f  which is associated with the outlet of the pump  112  is closed by being located between seals  164   f  and  164   g,  and port  154   g  which is associated with the irrigant lumen is closed by being located between seals  164   g  and  164   h.  In this third position of the spool  156 , two separate flow paths are provided, namely, port  154   a  which is associated with outlet of the pump  112  and port  154   b  which is associated with the reservoir  14  are in fluid communication via groove  162   a  due to the location of seals  164   c  and  164   d,  while port  154   e  which is associated with the retention balloon lumen and port  154   d  which is associated with the inlet of the pump  112  are in fluid communication via groove  162   b  due to the location of seals  164   e  and  164   f.  Thus, this configuration permits fluid to be pumped from the retention balloon lumen to the reservoir to, so as to deflate the retention balloon  24 . 
     In this manner, the spool valve  113  may replace the three solenoid valves, while providing numerous advantages. For example, the spool valve  113  advantageously requires a smaller footprint for the hydraulic control circuit within the base unit  12 . Also, a single actuator  115  may be used to move the spool  156 , replacing the three solenoids that otherwise are used for actuation of the three solenoid valves. Additionally, the spool valve  113  components may be molded or otherwise constructed of less expensive and lighter weight materials that do not corrode, such as polymer materials for the spool  156  and valve body  150 , and polymer or rubber materials for the seals  164   a - 164   h  disposed between the spool  156  and the bore  152  of the valve body  150 . 
     Indeed, the description of the Stages and general operation of the device  10  of the present disclosure proceeds in a manner somewhat similar to that which is described and shown with respect to FIGS. 1-14 of International Patent Application No. PCT/US17/41205. However, the single spool valve  113  and single actuator  115  replace the three solenoid valves. The spool valve  113  uses three positions to provide a hydraulic control circuit having the fluid flows similar to those discussed in International Patent Application No. PCT/US17/41205 for Stages 1, 2 and 3 of operation of the device  10 . The ports  154   a - 154   g  would be connected to the other components, including fluid connection of port  154   a  to an outlet of the pump  112 ; fluid connection of port  154   b  to the reservoir  14 ; fluid connection of port  154   c  to an inlet of the pump  112 ; fluid connection of port  154   d  to the inlet of the pump  112 ; fluid connection of port  154   e  to the retention balloon  154 ; fluid connection of port  154   f  to the outlet of the pump  112 ; and fluid connection of port  154   g  to an irrigant lumen of the tube  16 . 
     Accordingly, this disclosure provides a trans-anal irrigation device  10  having a spool valve  113 , with the device  10  including a pump  112 , an irrigation fluid reservoir  14  in fluid communication with the pump  112 , a rectal catheter  20  having a retention balloon  24  and an irrigant passage or main passage through the rectal catheter  20 . The device  10  includes fluid tubing having at least two lumens, a first lumen providing fluid communication between the pump  112  and the retention balloon  24 , and a second lumen providing fluid communication between the pump  112  and the irrigant passage. The spool valve  113  is part of a hydraulic control circuit including a spool valve  113  having a spool  152  that is movable by an actuator  115 . 
     The spool valve  113  includes a valve body  150  having an elongated bore  152 , and a plurality of ports  154   a - 154   g  spaced apart along and in fluid communication the bore  152 . The spool  156  further includes a plurality of lands  158   a - 158   c,  separated by a plurality of grooves  166   a - 166   h.  The spool  156  further includes seals  164   a - 164   h  extending outward from the lands  158   a - 158   c  and sealingly engaging the elongated bore  152  of the valve body. The plurality of ports  154 - 154   g  and plurality of seals  164   a - 164   h  and grooves  166   a - 166  are arranged for selectively directing flow alternatively from the reservoir  14  to the retention balloon  24 , for Stage 1 of a procedure and as shown in  FIG. 6 , from the reservoir  14  to the irrigant passage in the catheter  20 , for Stage 2 of a procedure and as shown in  FIGS. 5 and 7 , or from the retention balloon  24  to the reservoir  14 , for Stage 3 of a procedure and as shown in  FIG. 8 , each of which is based on the position of the spool  156  within the valve body  150 . 
     Thus, it will be appreciated that with the trans-anal irrigation device  10 , a first port  154   a  of the plurality of ports is associated with and fluidly connected to an outlet of the pump, a second port  154   b  of the plurality of ports is associated with and fluidly connected to the reservoir, a third port  154   c  of the plurality of ports is associated with and fluidly connected to an inlet of the pump, a fourth port  154   d  of the plurality of ports is associated with and fluidly connected to an inlet of the pump, a fifth port  154   e  of the plurality of ports is associated with and fluidly connected to the retention balloon, a sixth port  154   f  of the plurality of ports is associated with and fluidly connected to the outlet of the pump, and a seventh port  154   g  of the plurality of ports is associated with and fluidly connected to an irrigant lumen that is in fluid communication with the irrigant passage through the rectal catheter. The spool  156  of the spool valve  113  is movable linearly to at least three different hydraulic control positions. 
     It will be appreciated that the spool valve  113  may be used to perform a method of establishing fluid paths through a spool valve  113  in a hydraulic control circuit of a trans-anal irrigation device  10 , wherein the spool valve  113  comprises a valve body  150  having an elongated bore  152  and a plurality of ports  154   a - 154   g  spaced apart along and in fluid communication with the bore  152 , and a spool  156  that is movable within the bore  152 , and wherein the plurality of ports  154   a - 154   g  further include a first port  154   a  associated with a pump outlet, a second port  154   b  associated with a reservoir, a third port  154   c  associated with a pump inlet, a fourth port  154   d  associated with a pump inlet, a fifth port  154   e  associated with a retention balloon lumen, a sixth port  154   f  associated with a pump outlet, and a seventh port  154   g  associated with an irrigant lumen, with the method including at least three steps that correspond to the aforementioned Stages 1, 2 and 3. 
     Thus, the at least three steps include: (1) moving the spool  156  to a first position within the bore  152  of the valve body  150  wherein the second port  154   b  is in fluid communication with the third port  154   c  and the fifth port  154   e  is in fluid communication with the sixth port  154   f,  so as to establish fluid paths through the spool valve  113  from the reservoir  14  to the pump inlet and from the pump outlet to the retention balloon lumen, such as to perform Stage 1 of an anal-irrigation procedure, as shown in  FIG. 6 ; (2) moving the spool to a second position within the bore  152  of the valve body  150  wherein the second port  154   b  is in fluid communication with the third and fourth ports  154   c,    154   d  and the sixth port  154   f  is in fluid communication with the seventh port  154   g,  so as to establish fluid paths through the spool valve  113  from the reservoir  14  to the pump inlet and from the pump outlet to the irrigant lumen, such as to perform Stage 2 of an anal-irrigation procedure, as shown in  FIGS. 5 and 7 ; and (3) moving the spool  156  to a third position within the bore  152  of the valve body  150  wherein the first port  154   a  is in fluid communication with the second port  154   b  and the fourth port  154   d  is in fluid communication with the fifth port  154   e,  so as to establish fluid paths through the spool valve  113  from the retention balloon lumen to the pump inlet and from the pump outlet to the reservoir  14 , such as to perform Stage 3 of an anal-irrigation procedure, as shown in  FIG. 8 . 
     The method may further include use of an actuator  115  that may be connected to the proximal end  156   a  of the spool  156 , and which moves the spool  156  between the first, second and third positions. The method also may include wherein the spool valve  113  further includes a plurality of lands  158   a - 158   c  and a plurality of seals  164   a - 164   h  extending radially outward from the lands  158   a - 158   c  and sealingly engaging the spool  156  and the bore  152  of the valve body  150 . The plurality of ports  154   a - 154   g  and plurality of seals  164   a - 164   h  are arranged to selectively direct flow through the spool valve  113  based on the position of the spool  156 . 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention disclosed herein.