Hi My Husband Has Had Constant Diaorhea For 4 Weeks.stomach

Hi my husband has had constant diaorhea for 4 weeks.stomach pains which sometimes go down to his privates.pain eases after five to ten minutes each time he goes to the toilet which can be up to 12 times a day.has lost two stone in four weeks.wint go to his gp.he is 6 foot 4 and 10 stone 5 now.he is self diagnosing as ibs