"Water in lung" is not a precise medical diagnosis. It could mean liquid present in the plural space (pleurisy) or liquid present in the lung's alveoli (lung edema). Pleurisy is usually due to lung infection. Lung edema is usually bilateral and due to heart failure. Both conditions should not be connected with your stomach(s). Your stomach pain could be due to stomach ulcer(s) located in the bigger stomach part that remained cut off after stomach bypass. This "stomach" can not be accessed neither trough gastroscopy nor colonoscopy. It can be examined only with surgical intervention (laparotomy). Your symptoms can be also due to some post stomach bypass complication like anastomotic leakage. Stomach cancer should be also excluded.
Enlarged liver and chronic pancreatitis are conditions that you probably had before stomach bypass. According to your height and weight you became only a little underweight. Have you done any laboratory tests like: blood count, hemoglobin, sedimentation rate, occult blood, liver status etc.?