Coughing up yellowish brown and clear mucos two days after Gastric Bypass

Subject is my wife. Age 29.

She had a gastric bypass surgery 2 days ago

She is currently coughing up small bits of what looks like mucos to me. Small slimy brownish yellowish globs with white foam. Image: https://postimg.cc/MMvjn0cV

She is trying to drink 2-3oz of water per hour, but she has not eaten anything since the surgery two days ago other than about an ounce of pudding 7 hours ago.

Her stomach is gurgling a lot at the moment and she had a bout of diarrhea about 30 minutes ago.

She also has severe pain in her left shoulder/arm. Sometimes in the right as well. When she was still in the hospital and then later on the phone we did talk to the surgeon and nurses about this part and they believe she's just having an unlucky time with some trapped gas.

On her post OP X-Ray with contrast they said they were unable to rule out a leak, but the surgeon did not see any other symptoms of one.

The main concern I am contacting about is the coughing stuff up because I know coughing up something brown can be a sign of internal bleeding. My hunch is that it's just mucos but we want to be sure.