Їжа проходить через кишківник.

A natural pronunciation is roughly:

YI-zha pro-KHO-dyt CHE-rez kysh-KIV-nyk

A few helpful notes:

• Ї is pronounced yi.
• ж sounds like the s in measure.
• х is like a throaty h/ch sound, not the English k.
• Stress usually falls like this:
  • ї́жа
  • прохо́дить
  • че́рез
  • кишкі́вник

So the whole sentence sounds approximately like:

YI-zha pro-KHO-dyt CHE-rez kysh-KIV-nyk

Ukrainian has no articles, so there is no separate word for the or a/an.

So:

• Їжа can mean food, the food, or sometimes some food
• кишківник can mean intestine, the intestine, or the intestines/gut, depending on context

English requires articles, but Ukrainian does not.

Їжа is the subject of the sentence, so it is in the nominative case.

Here it means food as a general noun.

Useful details:

• dictionary form: їжа
• gender: feminine
• number: singular

Because it is the subject, it stays in its basic form:

• Їжа проходить... = Food passes/goes...

Here проходить means passes, goes through, or moves through.

It comes from the verb проходити, which often means:

• to pass
• to go through
• to move through
• sometimes to undergo in other contexts

In this sentence, it describes movement through something:

• Їжа проходить через кишківник = food passes through the intestine/gut

This is present tense, third person singular:

• він/вона/воно проходить = he/she/it passes

Because їжа is singular, the verb is singular too.

Ukrainian present-tense verbs change according to person and number.

The verb проходити conjugates like this in the present:

• я проходжу = I pass/go through
• ти проходиш = you pass
• він/вона/воно проходить = he/she/it passes
• ми проходимо = we pass
• ви проходите = you pass
• вони проходять = they pass

Since їжа is grammatically singular, Ukrainian uses:

• їжа проходить

Even though English says food without obvious singular marking, Ukrainian treats їжа as a singular noun.

Через is the preposition that usually means through or sometimes across.

So:

• через кишківник = through the intestine/gut

It is the natural choice when something physically passes from one side/part to another through a space or organ.

Compare:

• йти через парк = to go through/across the park
• проходити через тунель = to pass through a tunnel
• їжа проходить через кишківник = food passes through the intestine

Because через normally requires the accusative case.

The dictionary form is:

• кишківник = intestine, gut

For this masculine inanimate noun, the accusative singular is the same as the nominative singular, so it still looks like:

• кишківник

So even though the form does not visibly change, grammatically it is accusative after через.

This is very common in Ukrainian:

• через парк
• через ліс
• через кишківник

All of these are accusative after через.

Ukrainian often uses singular where English prefers plural.

Кишківник can mean:

• the intestine
• the intestines
• the gut
• the intestinal tract

So even though English often says the intestines, Ukrainian can naturally use the singular кишківник.

That does not sound strange in Ukrainian.

Usually it sounds like a general fact or a scientific/biological statement:

• Food passes through the intestine
• Food goes through the gut

Ukrainian present tense often covers both:

1. something happening now
2. a habitual action
3. a general truth

So without extra context, this sentence is most naturally understood as a general statement about digestion.

Yes. Ukrainian word order is more flexible than English, although not completely free.

The neutral order here is:

• Їжа проходить через кишківник.

You may also see different orders for emphasis, for example:

• Через кишківник проходить їжа.
• Кишківник їжа проходить через... — this one is much less natural and would usually need a special context

The original sentence is the most normal and straightforward way to say it.

It is a very common and standard word for intestine / gut / intestinal tract.

Related words include:

• кишка = intestine, bowel (often one intestinal tube, more anatomical or specific)
• кишки = intestines, bowels
• кишківник = intestine/gut/intestinal tract as a system or organ area

In a simple educational sentence like this, кишківник is a very natural choice.

You can change the tense like this:

• Їжа проходила через кишківник. = Food was passing / used to pass through the intestine.
• Їжа пройшла через кишківник. = Food passed through the intestine.
• Їжа проходитиме через кишківник. = Food will pass through the intestine.
• Їжа пройде через кишківник. = Food will go/pass through the intestine.

A useful pattern here is:

• проходити = imperfective, process / repeated action
• пройти = perfective, completed action

So:

• проходить focuses on the process or general action
• пройде / пройшла focuses more on completing the passage

A close breakdown is:

• Їжа = food
• проходить = passes / goes through
• через = through
• кишківник = intestine / gut

So the structure is:

Food passes through intestine/gut

In normal English, you add the article and choose the most natural body-term:

• Food passes through the intestine
• Food goes through the gut
• Food passes through the intestines depending on context