A 28 year old male admitted in the hospital with a history of vague pains. His examination revealed many scars of previous surgeries. He was very curious about knowing his diagnosis and was persistently asking for various diagnostic procedures and biopsy. He gave the past history of gall stone & appendicitis pain diagnosed by previous doctors, but the history regarding this was inappropriate and seemed to be manipulative. There were no previous records suggesting this diagnosis. The probable diagnosis is-