Method and devices for selective endoscopic retrograde cholangiopancreatography

1. A method for inserting a catheter having a primary lumen with a first front opening into a bodily structure, comprising:

inserting a catheter into the bodily structure;

activating one or more points of negative pressure on the catheter to engage an inter-mural mucosa of the bodily structure;

pulling back the catheter thereby pulling the inter-mural mucosa taut and minimizing an obstruction of the first front opening caused by the inter-mural mucosa; and

inserting a device through the first front opening of the primary lumen of the catheter into the bodily structure.

2. The method of claim 1 , wherein the pulling back occurs while the device, comprising a thinner catheter or guidewire, is passed through an internal canal of the bodily structure made taut by the pulling back.

3. A method for inserting a catheter having a primary lumen into a bodily duct structure, comprising:

inserting a catheter into the bodily duct structure;

activating one or more points of negative pressure on the catheter to engage an inter-mural mucosa of the bodily duct structure;

pulling back the catheter thereby pulling the inter-mural mucosa taut; and

inserting a device through the primary lumen of the catheter into the bodily duct structure.

4. The method of claim 3 , wherein the bodily duct structure is a naturally occurring ampullae structure.

5. The method of claim 3 , wherein the bodily duct structure is a naturally occurring bile duct structure.

6. The method of claim 3 , wherein the bodily duct structure is a naturally occurring pancreatic duct structure.