Seal for a rectal or ostomy appliance

1. A rectal appliance comprising:

a tubular member defining a communication passage for body waste;

a membrane carried on said tubular member, said membrane at least partly defining:

(i) a first inflatable chamber portion for forming an internal seal against internal tissue of the anus;

(ii) a second inflatable chamber portion for forming an external seal against perianal tissue;

wherein at least a portion of the membrane is fixed relative to said tubular member at an intermediate position intermediate the ends of the tubular member to define a narrow waist region between the first and second inflatable chamber portions; and

(iii) a plurality of corrugated inflatable columns intermediate the ends of the tubular member, defining passageways for inflation fluid and pathways for escape of flatus.

2. The rectal appliance according to claim 1 , wherein said fixation of the membrane relative to the tubular member at said intermediate position is such as to define said passageways for inflation fluid between the first and second inflation chamber portions and pathways for escape of flatus.

3. The rectal appliance according to claim 2 , wherein at said intermediate position, the membrane is secured by a discontinuous seal defining said corrugated inflatable columns.

4. The rectal appliance according to claim 1 , wherein the tubular member is supported at least partly by said corrugated inflatable columns.

5. The rectal appliance according to claim 1 , wherein, in use, at least one of the first and second chamber portions has a generally flared shape extending from the waist.

6. The rectal appliance according to claim 5 , wherein both inflatable chamber portions have a respective flared shape.

7. The rectal appliance according to claim 1 , wherein the tubular member comprises a flange at or near one end thereof.

8. The rectal appliance according to claim 7 , further comprising a closed loop shape flexible or elastic wall connecting the membrane to the flange.

9. The rectal appliance according to claim 8 , wherein the closed loop shape flexible or elastic wall provides a volumetric reserve and/or an elastic rebound to the device.

10. The rectal appliance according to claim 1 , further comprising an inflation port for inflating the first and second chambers in common.

11. The rectal appliance according to claim 1 , further comprising a dedicated deflation port for deflating at least one of the first and second chambers.

12. The rectal appliance according to claim 1 , wherein the first inflatable chamber portion has a closed loop shape and is located around the tubular member, for sealing against internal tissue.

13. The rectal appliance according to claim 12 , wherein said tubular member has a distal end, and the first inflatable chamber portion is predeterminedly dimensioned so when inflated the first inflatable chamber portion forms a closure in front of the distal end of the tubular member.

14. The rectal appliance according to claim 13 , wherein the closure is openable to discharge waste by partially deflating and/or reducing the pressure within the first inflatable chamber portion while retaining enough pressure to maintain the appliance in place.

15. A rectal appliance comprising:

a tubular member defining a communication passage for body waste; and

an external inflatable chamber portion of closed loop shape located around the tubular member, for sealing against perianal skin, the external inflatable chamber portion being defined at least partly by a flexible membrane and a flexible or elastic rear wall that are mutually attached together along a seam of closed loop shape and, a plurality of inflatable columns intermediate the ends of the tubular member, defining passageways for inflation fluid and;

an internal inflatable chamber portion of closed loop shape located around the tubular member, for sealing against internal tissue.

16. The rectal appliance according to claim 15 , wherein the seam at least partly constrains the inflated shape of the external inflatable chamber portion.

17. The rectal appliance according to claim 15 , further comprising a flange at or near an end of the tubular member, and wherein the flexible or elastic rear wall connects the membrane to the flange.

18. The rectal appliance according to claim 15 , wherein the flexible or elastic rear wall has a different material characteristic from the membrane, said different material characteristic including one or more of: different material; different thickness; different flexibility; different elasticity; different resistance to punctures.

19. A rectal appliance comprising:

a tubular member defining a communication passage for body waste, and carrying a flange at or near one end;

an external inflatable chamber portion of closed-loop shape and located around the tubular member, for sealing against perianal skin, the external inflatable chamber portion having a shape defined at least partly by the flange and a plurality of corrugated inflatable columns intermediate the ends of the tubular member defining passageways for inflation fluid and pathways for escape of flatus and;

an internal inflatable chamber portion of closed loop shape extending around the tubular member, for sealing against internal tissue.

20. The rectal appliance according to claim 19 , wherein the external inflatable chamber portion comprises at least one flexible wall supported by the flange.

21. The rectal appliance according to claim 20 , wherein the external inflatable chamber portion further comprises a flexible membrane coupled to the flexible wall, and wherein the flexible wall is coupled to the flange.