Seeds of buckwheat (Fagopyrum esculentum) - ripe ovules, peeled - we call buckwheat. It belongs to the products recommended for many gastroenterological diseases, and buckwheat for gastritis is also included in the diet. 
The benefits of buckwheat
But first, about the benefits of buckwheat, which is a rich source of vegetable protein, starch and dietary fiber, fatty acids (including unsaturated ones - linoleic and linolenic), vitamins, macro- and microelements , polyphenolic compounds (in the form of flavonoids), etc..
And all these useful substances of ordinary buckwheat porridge are well absorbed, since the content of phytic acid, which interferes with their absorption, is minimal in buckwheat compared to cereals.
Balanced in composition, buckwheat vegetable proteins are distinguished by a high content of the essential amino acid lysine, which promotes healing - the regeneration of damaged tissues. And the combination of lysine with the proteinogenic amino acid glycine (which is not an essential one) contributes to the regulation of hepatic LDL receptors (low density lipoproteins) and lower blood cholesterol levels. Also, the mechanism for lowering lipid levels in blood serum is associated with buckwheat flavonoids, which inhibit the activity of lipase, a digestive enzyme produced by the pancreas.
Studies of biologically active components of buckwheat seeds have shown the presence in them of a number of antioxidant enzymes that protect cells from oxidative stress - the harmful effects of superoxide radicals (reactive oxygen species).
The flavonoid quercetin present in buckwheat, in addition to its antioxidant effect, reduces the intensity of inflammatory processes, helps to stabilize the cell membranes of various tissues. For patients with inflammation of the gastric mucosa, the benefit of this plant polyphenol is a positive effect on the entire gastrointestinal tract: it accelerates the regeneration of damaged tissues (including the mucous membrane of the stomach and intestines) and, in fact, has a gastroprotective effect. 
In addition, recent studies (in vitro and in vivo) have demonstrated the ability of quercetin to reduce gastric mucosal inflammation and cell death associated with Helicobacter pylori infection .
It has a strengthening effect on the walls of blood vessels and reduces bleeding of capillaries.
Buckwheat also contains thiamine (vitamin B1), riboflavin (vitamin B2), pyridoxine (vitamin B6), folic acid (vitamin B9), niacin (vitamin PP).
Tannins of buckwheat seeds, interacting with the proteins of mucus produced by the glands of the stomach, increase the protection of its mucous membrane.
The benefits of buckwheat are indisputable in the chemical elements contained in it, which are necessary for many biochemical processes in the body: potassium, magnesium, phosphorus and manganese; iron and copper (which contribute to the normal functioning of the immune system); zinc (participating in many cellular processes of tissues of all systems and organs), etc. 
Can buckwheat with gastritis?
Due to its biochemical composition, buckwheat is considered one of the most beneficial for the body, and almost no diet for gastrointestinal diseases can do without it . And, first of all, it concerns a diet for gastritis .
But gastritis can be different - depending on the acidity of gastric juice, the level of which is due to the production of hydrochloric acid by the fundic glands of the stomach.
Buckwheat is allowed and even welcomed for gastritis with high acidity. Read:
Buckwheat with erosive gastritis can be used only in the stage of remission of the disease, since buckwheat seeds contain organic acids (carboxylic and phenolic), in particular, oxalic and salicylic.
Buckwheat porridge is also recommended in a diet for atrophic gastritis with low acidity , but to facilitate digestion in the stomach, it should be viscous.
Buckwheat during exacerbation of gastritis is used in the form of mashed liquid porridge, boiled in water. See - Diet for exacerbation of gastritis
Uncooked raw or green buckwheat for gastritis - despite its powerful antioxidant and other beneficial properties - is not recommended by most dietitians: porridge from such buckwheat is often bitter, takes longer to digest in the stomach and can cause constipation and increased formation of gases in the intestines. 
How to cook buckwheat with gastritis?
You need to cook buckwheat with gastritis correctly. The sorted and washed cereals are placed in a saucepan or saucepan, poured with boiling water (two or three parts of water for one part of the cereal), after boiling, the fire is reduced. The dishes are covered (leaving a gap) and kept on low heat - so that the cereal is properly boiled. Then put butter (quite a bit) and cover the pan completely.
More liquid and viscous porridge will be if the cereal is poured with cold water, but then it will take more time to cook it.
By the way, in order not to wipe the porridge from the core (whole seeds), they prepare viscous or liquid porridge from buckwheat chopped: it contains the same useful substances and cooks faster. Buckwheat with milk for gastritis (especially with an increased level of acidity of gastric juice) can be prepared with a mixture of water and milk - in a ratio of 1:2 or 1:1.
In addition to porridge, recipes include soup with buckwheat in vegetable or diluted chicken broth, see - Recipes for soups for gastritis
They also prepare cutlets, zrazy or casseroles based on boiled buckwheat. For example, to prepare buckwheat steam cutlets, two parts of buckwheat are mixed with one part of boiled potatoes (mashed to a puree), some boiled grated carrots and finely chopped fresh herbs are added. Instead of potatoes, you can put boiled chopped chicken fillet. Cutlets are formed from a well-mixed mass and steamed.
Among the possible complications of eating buckwheat for gastritis, only a very rare allergy to buckwheat is noted .