The moral of the story: when you have an unexplained small bowel obstruction in a young female, consider endometriosis. 

After repeated imaging, the ill-defined transition point in the pelvis becomes more apparent as small-bowel thickening and enhancement. This does not appear typical for inflammatory bowel disease, although that would be a consideration in addition to endometriosis. The MRI was much less impressive given the disease burden seen on laparoscopy (confirmed also with biopsy).