Blood in stool , Lumps in leg abdomenetc

Hello Doctors , My self is 22 , I have notices some blood in stool earlier this month , These occurred to me in last year also , the same month . I have gas issues from childhood.Since last month I am feeling constipated.Now I saw lumps above groin,in legs , And in chest - varies in size , Nothing visible to eye .Deep under skin.Some lumps feels like filled with fluid.Stool size is normal.But consistency varies some time. I have joint pain also.Severe in arm joints.Burning like pain.What may be the reason.The blood in tool occurred previously about the same time.In the month of August.No weight loss till now.In fact weight has increased.Which I intentionally did.What may be the reason.Which specialist should I meet.What tests should I do? Anxiety is killing me!