The aim of the study was to evaluate the effectiveness of polisorbin drug for the treatment of gastrointestinal diseases of nutritional origin in calves. The scientific-production experiment was performed on the basis of the Collective Farm “Iskra” of the Kuzhenersky district of the Republic of Mari El, where two groups of calves of black-motley breed at the age of 2 days were chosen by analogy. Each group included five animals with symptoms of disorders of the gastrointestinal tract. Calves of the experimental group individually with colostrum received polisorbin at 100 mg/kg of body weight 2 times a day. The calves of the control group did not receive sorbents. Treatment of this group of calves was performed with enrofloksotsin drug at 2,5 mg/kg of body weight once a day. Duration of the experiment was 10 days. Before starting the experiment study on the content of feed microscopic fungi and mycotoxins was carried out. Infectious diseases were excluded. Mycological study found high extent of defeat of forages with fungi Aspergillus genera, Fusarium, Penicillium, and myco-toxicological analysis found in mycotoxins in feed: aflatoxin B1, patulin, zearalenone. The study found that the experimental group of calves during treatment with the drug polisorbin (100 mg/kg of body weight) demonstrated improvement in general condition on the second study day, a full recovery of calves in this group occurred on the fifth day of treatment. At 10 days of age the experimental calves were transferred to the general group.