painful, bloody diarrhea

For about 6 months now my husband has been having constant bloody diarrhea. The last 3 months abominal pain has slowly started and now to the point where he can barley function without pain meds. The whole lower abdominal area is painful. He states that when he has a bowel movement which is about 3-4 times a day it hurts his abd as he says it feels as if someone is pushing into is stomach and feels like someone is pouring acid in his anus. Other symptoms he has been experiencing is hot flashes. Lots of sweating and sometimes turns pale.
He has has a CT, blood work, endoscopy and colonoscopy. Everything came back normal with a few small finding. Small internal hemorroids red spots in his lining (some word that starts with an E). Tested stools - Normal. bloodwork for iron, anemia - normal.
New symptom recently told me he had blood in his urine and hard to urinate. Went in to the doctors and ordered a CT urogram. Found a kidney stone. This feels like its the beginning of getting him better but this doesn't explain the continuous bloody diarrhea and sever abd pain or hot flashes. Please help!!