The pharmaceutical composition is a combination of hydrolytic lignin with moisture of 55% to 65% consisting of the particles measuring 0.15 mm to 0.55 mm, a 45% to 55% aqueous lactulose solution, and a 50% to 55% aqueous oligosaccharide solution at the following ingredient ratio (weight percent): an aqueous lactulose solution: 10/60; oligosaccharides: 10/50; hydrolytic lignin: quantity sufficient. Hydrolytic lignin, lactulose and fructose oligosaccharides are sequentially added and mixed using a rotor blender. The composition is administered orally for no less than 14 days and no more than 30 days, two to four times a day, depending on the patient's weight and age. The composition is used as a medicine for treatment of the gastrointestinal disorders, including bacterial, viral, protozoal enteric infections, food poisoning, acute and chronic hepatitis and cirrhosis, diarrhea, peptic ulcer, Crohn's disease, ulcerative colitis, irritable bowel syndrome, mineral disorders with Ca/Mg deficiency, including osteoporosis and other alterations of the bone formation, as an immunomodulator in atopic dermatitis and immunodeficiency conditions, for protection and recovery of intestinal flora after antibiotic therapy, chemotherapy, and radiotherapy. The result is accelerated achievement of the effect and the enhanced action on the state of intestinal microbiocenosis as well as increased effectiveness of treatment of hepatitis and liver cirrhosis, elimination of undesired adverse effects in clinical usage, and extension of indications, i.e. the extended spectrum of usage in prevention and treatment.