I need to take motrin for a week or 2 for injury, have a sensitive stomach. already take with food. would it help to take with gaviscon or similar?

Motrin: If your stomach is already being irritated then its best you stop the Motrin - would suggest something like arthrotec, (diclofenac and misoprostol) or duexis.

Add acid blocker: Motrin & all nsaids can reduce blood flow and mucus production in the GI tract increasing risk of mucosal injury especially ulcers. Taking an acid blocker may partially reduce the risk. A "cytoprotective" medication sucralafate/carafate or Misoprostol may also reduce the risk.

Maybe: Motrin can irritate the stomach lining leading to gastritis and/or ulcers. Taking antacids can help prevent this. If you are already having symptoms, it might be best to stop the Motrin until they resolve.