Hi. Thanks for your query. Noted the history of negative pregnancy tests, constipation to the tune that you visit toilet once in a week, took prune juice and the stools are oily. The stools can be oily if there is no bile salts and pigments or pancreatic lipase deficiency in the pancreatic juice. Another reasons can be oily food that you might have ate or the mucus appearing as oily thing. Anyways you need the following: Continue prune juice in lesser quantity. Laxative to soften the stool. Suppository daily to train your bowel to pass stool daily. Investigations like liver function tests, thyroid functions, stool and urine. Ultrasonography and X-ray of the abdomen. This will confirm the diagnosis and you will get the results.