Many types of diarrhoeal diseases, with many different causes, disrupt bowel function. The capacity of the probiotics reduce the incidence or duration of diarrheal diseases is perhaps the effect more verified on the health of the probiotics. A paper published in 2002 reviewed nine studies on effect of Lactobacillus as therapy for diarrhoea in children. This paper concluded the Lactobacillus is safe and effective as a treatment for children with acute infectious diarrhea. Although this meta-analysis may criticize by combining data from various species and strains of Lactobacillus in an analysis, the positive nature of the conclusion suggests that at least for this indication and for these strains, they have obtained positive results. A common form of diarrhea is that associated with the consumption of antibiotics. The purpose of antibiotics is to kill harmful bacteria.

Unfortunately, they can also kill benign bacteria, and thus disturbing the normal bowel function. It is important that the microbiota of healthy person is absolutely resistant and will return to a State of the pre-antibiotico without intervention. But it is presumed that and minimize disruptive effects. A recent study documented that a probiotic containing four of Lactobacillus and Bifidobacterium strains led to a more rapid return to normal microbiota in adults fed antibiotics. A paper published in 2002 reviewed seven studies (881 patients in total) on the impact of probiotics in diarrhea antibiotico-asociada supplements. The paper concluded that the but that there is no strong effect on the ability of probiotics to treat such diarrhea. How the probiotic achieves this task is not known.

Not all studies have shown positive results in the prevention of antibiotic-associated diarrhea or other symptoms associated with therapy with antibiotics. A serious complication of antibiotic therapy can be the beginning of colitis due to Clostridium difficile. This condition may be refractory to treatment antibiotic subsequent resulting repetitions on course. Some small studies have suggested that certain probiotics can prevent relapses of colitis of C. difficile. A recent meta-analysis concluded that the probiotic yeast, Saccharomyces boulardii was the most effective probiotic treatment. Another common form of diarrhea is experienced by travellers. Studies that evaluate the effect of probiotics on travelers diarrhea supplements is ambiguous. There is a need for further research in this area for more convincing results. A meta-analysis of 12 studies on travelers with diarrhea concluded that certain.