Thank you for the query.Rheumatoid arthritis
like symptoms can appear many years before intestinal manifestation of Crohns disease
. Main symptoms of Crohns disease are loose stools, blood in the stool, mucus in the stool, weight loss
Crohns disease is a kind of issue where host immune system destroys particular tissues in own body. That is why joint pains and skin lesions can appear.
I suggest your friend to visit gastrologist. Stool tests and colonoscopy
should be done.
Hope this will help.