If you just ate or are squeamish, stop reading this now. The past two weeks for Washington Nationals left-handed reliever Felipe Rivero have been harrowing. He surprisingly landed on the disabled list on April 22 after making only one appearance, his major league debut only a few days earlier. The injury that put him there was announced by the Nationals as “GI bleed,” essentially gastrointestinal bleeding.

But, in reality, it was worse than it sounded. Rivero first noticed something was wrong on April 21. He was at a team event earlier in the day and felt faint. During the game, he got up to warm up. The 23-year-old said he threw two pitches and went to throw up. The color was black because of blood.

“I tried to stay calm to not make it worse,” Rivero said in Spanish on Monday.

Rivero told team officials and he immediately went for tests. It turns out Rivero had an ulcer in his stomach that burst. Rivero said doctors told him that perhaps his frequent use of a common over-the-counter anti-inflammatory, which he took for years in between starts when he was in the minors to help with recovery, may have thinned his stomach lining. And finally, it gave out.

“I was nauseous,” Rivero said. “I didn’t feel like I had any strength. It hurt.”

A day after he reported feeling ill, Rivero said he had a procedure which patched up his stomach with staples using tubes inserted down his mouth. Rivero spent the night at the hospital. He said he doesn’t feel any pain any more.

All Rivero could eat the first few days was soup and liquids. He has slowly gained strength, felt better and graduated to solid foods — but no chocolate or fatty food. He has been doing light activity, such as throwing from flat ground. He met Class AA Harrisburg in Bowie over the weekend to work out with them while the Nationals were on the road. He threw lightly again Monday with the Nationals back in town.

“Sometimes I don’t feel well but I’m getting there,” he said. “Little by little. [Sunday,] when I did flat ground, I was too tired. I did flat ground [Monday] and it was a little bit better. I wasn’t as tired.”

The Nationals took blood samples Monday to test Rivero’s improvement so far, Manager Matt Williams said. Rivero said he isn’t sure when he could begin a minor league rehab assignment but he is happy to be feeling better and with more stamina than before.