Chaya,
The subject is a very complicated one and there are many GI problems associated with SLE. I personally had dysphagia and still have Barretts esophagus and something resembling IBS although I don't have that in the opinion of my doctors. When I was near death one of the reasons my case was so drug resistant was that my intestines were not absorbing meds or food properly and my meds were switched to IV. I also have diverticulosis but there is no agreement if that was caused by my illness or something else.
Here is a long article on the subject and will give you some idea of the complexity and also the lack of total understanding of the subject. It requires downloading a 16 page pdf file that you can read and/or save to your computer.
http://rheumatology.oxfordjournals.org/cgi/reprint/38/10/917
My impression of my own problems is that nothing in my GI tract is functioning like it were 3 years ago. I believe, as do my doctors, that the disease hit my entire GI tract in one way or another.
Also, you talk about "familial" diseases....they are all related in the sense that they are auto immune. Studies have shown that auto immune diseases tend to run in families however not necessarily the same ones. Most of us have other relatives who have some sort of auto immune diseases but not the one(s) we have. And most of us have several....lupus, scleroderma, and polymyositis in my case as well as other secondary conditions caused by the primary disease(s). All of this shows the systemic nature of auto immune diseases and how a misdirected immune system can produce so many different diseases and symptoms. Lupus has been called the disease with a 1000 faces and it often mimics other diseases which makes diagnosis so difficult in some patients. In my case, I actually have mixed connective tissue disease which is much rarer than lupus and usually exhibits symptoms of at least 3 diseases. Normal definition is sle, scleroderma and polymyositis but some also have RA, dermatomyositis, sjogrens, and others. Very confusing. Like lupus every patient is different so there is no standard set of symptoms, treatment, or outcome. Frustrating and scary but that is the nature of these horrible diseases.
It sounds like you are still in search of a diagnosis but there are many possibilities from lupus alone or you could have another AI disease. AI diseases are not like a viral or bacterial disease where there is a known agent that causes a certain set of symptoms. With AI diseases there is a set of genes that predispose our immune systems to a disruption and then something else acts as a trigger. In most cases we never know what that trigger is. It isthought that some of us might have an early trigger bringing our immune system to the brink but not showing any outward symptoms. Then another trigger pushes it over the brink and causes an attack on some part of our body. The whole mechanism is not understand but it is very complex and until researchers understand which genes, and what the cellular mechanisms and chemistry are that cause a specific set of symptoms there is a lot of guessing.
I had kidney involvement and had low normal BP but had a condition called proteinuria which caused very extreme edema in my case. Fortunately, there was little damage and meds (lisinopril and lasix) helped to put things in order again. A year later my BP shot up due to prednisone and I am still fighting that with meds.
Sorry you are having so much difficulty getting a diagnosis but after several years of this I have forgotten what it is like to be normal. My disease was diagnosed fairly early but it has taken a year and half to diagnose all the secondary conditions and diseases that have resulted. No fun.
Keep pushing your doctors for answers and explanations. We are all trying to understand something that is not yet understood and is extremely complex. The study of our genes in relation to AI diseases has just begun and there has been some progress in understanding the mechanisms of some diseases. Lupus is fairly widespread and there is a lot of research going on. My muscle disease, polymyositis, forget it. Too rare and almost unknown. I will probably be long gone by the time they understand and find a specific treatment and cure. Right now AI diseases are treated by "tranquilizing" our immune systems with corticosteroids or immuno suppresants....not by treating the disease itself.
I know none of this is comforting but we are all in the same frustrating boat to some degree. Hang in there and keep pushing for answers.
Bill