What Causes Swelling In Between The Groin And Foot Of A OCD Patient?

I am the close friend and care giver of a man who takes antipsychotic drugs, diazepam, and neurontin. he has schizo-affective disorder and severe OCD. He has been on many, many, almost all, psychoactive medications. in fact he is for the most part refractory to the medications. The one medication that seemed to help him years before was Lithium. About 9 years ago he grew almost silent and had no interest at all. He was also urinating on himself and his legs were hugely swollen from foot to groin. The family practice doctor could find nothing wrong and prescribed a diruretic, but the swelling did not go down. He said the urinary problem was mental. But a new psychiatrist began slowly withdrawing Lithium thinking it might be the culprit even though his levels were still in the non toxic range. He had to be hospitalized due to a big shift in his behavior, manic symptoms, but the hospital took him off the rest of the Lithium and within two days the incontinence stopped and the swelling went down. We were told for him to never have lithium again. Now eight years later another doctor wants him to try it again since nothing else has worked and he is always manic and angry now. Now other mood stabalizers work. Do you think he should ever go back on a drug that caused him such dramatic physical problems? Since he was not toxic how do we explain the improvement?