Gastritis is an inflammatory disease leading to abdominal pain, nausea, and diarrhea. While therapy depends on etiology, adhesive agents protecting the gastric tissue represent a promising treatment option. Caricol-Gastro is an organic product that significantly decreased gastritic abdominal pain in a recent clinical study. To investigate whether this beneficial effect can be attributed to the formation of a protective layer covering the gastric mucosa after oral application, several methods were used to determine adhesion. These include macro-rheological measurements and gastric mucin interactions, which were correlated to network formation, examined by Cryo-scanning electron microscopy technique, wettability via sessile drop method on human gastric adenocarcinoma cell layers, and ex vivo adhesion studies on gastric porcine tissue with the falling liquid film technique considering physiological conditions and Franz diffusion cells for quantification. The results showed that Caricol-Gastro formed a stable viscoelastic network with shear thinning properties. It exhibited high wettability and spreadability and adhered to the excised gastric mucosa. We found that oat flour, as the main ingredient of Caricol-Gastro, supports the gel network regarding viscoelasticity and, to a lesser extent, adhesion in a concentration dependent manner. Moreover, our data highlight that a variety of coordinated methods are required to investigate gastric adhesion.