I Have Had Diarrhea Off And On For Several Weeks

I have had diarrhea off and on for several weeks now and it is lose and runny. I am 51 years old. I have had two hernia repair surgeries, (one last year and have about 20 inches of mesh in my abdominal area. I have marks on my underwear most days from lose stools. I still have my period and for the last few days heavy flow of blood.