A device for treating a patient for obesity and/or type II diabetes comprising: - a duodenal anchor (550, 600, 601) sized and shaped for residing in a proximal portion of a duodenum of the patient, the anchor being configured to exert a radially directed force against the inner walls of the proximal portion of the duodenum; and - a flexible tube member coupled to the duodenal anchor and configured for extending through at least a portion of the duodenum of the patient; the duodenal anchor comprising: o a support member (552, 604) having open proximal and distal ends, wherein the support member has an outer wall and an inflatable membrane coupled to the outer wall and wherein the inflatable membrane is expandable to a size that exceeds the maximally dilated size of a human pylorus, wherein the inflatable membrane has proximal and distal end portions characterized in that the proximal end portion has a larger diameter in an inflated configuration than the distal end portion; and o characterized in that the duodenal anchor comprises a biasing mechanism being coupled to the support member and exerting a radially directed outward force against the support member, wherein the biasing mechanism comprises a spring enclosed within the support member or an annular rib enclosed within the support member, the spring or the annular rib providing the outwardly directed force against the support member. - a duodenal anchor (550, 600, 601) sized and shaped for residing in a proximal portion of a duodenum of the patient, the anchor being configured to exert a radially directed force against the inner walls of the proximal portion of the duodenum; and - a flexible tube member coupled to the duodenal anchor and configured for extending through at least a portion of the duodenum of the patient; the duodenal anchor comprising: o a support member (552, 604) having open proximal and distal ends, wherein the support member has an outer wall and an inflatable membrane coupled to the outer wall and wherein the inflatable membrane is expandable to a size that exceeds the maximally dilated size of a human pylorus, wherein the inflatable membrane has proximal and distal end portions characterized in that the proximal end portion has a larger diameter in an inflated configuration than the distal end portion; and o characterized in that the duodenal anchor comprises a biasing mechanism being coupled to the support member and exerting a radially directed outward force against the support member, wherein the biasing mechanism comprises a spring enclosed within the support member or an annular rib enclosed within the support member, the spring or the annular rib providing the outwardly directed force against the support member. o a support member (552, 604) having open proximal and distal ends, wherein the support member has an outer wall and an inflatable membrane coupled to the outer wall and wherein the inflatable membrane is expandable to a size that exceeds the maximally dilated size of a human pylorus, wherein the inflatable membrane has proximal and distal end portions characterized in that the proximal end portion has a larger diameter in an inflated configuration than the distal end portion; and o characterized in that the duodenal anchor comprises a biasing mechanism being coupled to the support member and exerting a radially directed outward force against the support member, wherein the biasing mechanism comprises a spring enclosed within the support member or an annular rib enclosed within the support member, the spring or the annular rib providing the outwardly directed force against the support member.