Pyrrolo-pyridazines with protective effects on the stomach and intestines.

Compounds of formula (I), where R1 ALKYL or substituted alkylene THROUGH R5; R2 alkyl; R3 hydrogen, halogen, CHO (formyl), hydroxymethyl, nitro, amino or the substituent -CH 2 O-COR7; R4 halogen or the substituent -AB-R6; R5 furyl, thienyl, tetrahydrofuryl, phenyl or phenyl substituted by one or two substituents GROUP identical or different halogen, alkyl or alkoxy; R6 hydrogen, thienyl, furyl, phenyl or substituted by one or two substituents GROUP identical or different halogen, alkyl, alkoxy, nitro, ureido, amino, and alkoxy carbonylamino ALQUILCARBONILOAMINO; R7 alkyl, alkoxy LQUILO; A oxygen or NH; B LINK LINEAR, -CH2 (methylene), or -CH2-CH2- (1,2-ethylene) and n the number 0 to 1, are novel compounds which are used for the prevention and treatment of gastrointestinal diseases.