Causes of diarrhea all the time: First, infection: including viruses, such as rotavirus, norovirus, coxsackievirus, echovirus; bacteria such as Escherichia coli, salmonella, shigella, dysentery bacillus, vibrio cholerae or parasites, such as lyso-organic ameba protozoa, pear-shaped flagellates caused by intestinal infections. Second, poisoning: food poisoning such as eating uncooked lentils, puffer fish poisoning, heavy metal poisoning, pesticide poisoning, etc. Third, drugs: laxatives, cholinergic drugs, digitalis-type drugs, etc. can cause diarrhea. Fourth, other diseases: such as acute attacks of ulcerative colitis, acute necrotizing enterocolitis, food allergies, etc. can cause diarrhea all the time.