Dysentery or Invasive diarrhea, is defined as diarrhea with visible blood or mucus, in contrast to watery diarrhea. Dysentery is commonly associated with fever and abdominal pain.
Common during the war was Typhoid , a cause of acute dysentery , caused by the Salmonella Typhi bacteria.
Typhoid was spread by ingesting contaminated food and water or through close contact with someone that was infected. It was particularly virulent in the crowded army camps during the first year of the war and throughout the war in the general hospitals.
Patients developed skin lesions called "rose spots," diarrhea or constipation, fatigue, respiratory distress, fever, and general malaise.
Thousand of people died and those who seemed to get better still could spread the disease to others for many months afterwards contributing to its further spread.
I'm not really sure what disease they were referring to by chronic diarrhea, but I'll see if I can find something.