In oct 2011, I had a severe heartburn incident in which I took 4 Pepcid complete tablets in 12 hours. Over the next several days, I have developed a severe lower left intestinal pain that radiates in the side and back area. The painful spot is permanent and will not go away. Antibiotics have helped, but only to a point. I cannot sleep on my left side, the pain that arises is terrible. Is this necrotising entercolitis? I am 52 yrs old with a history of IBS and excessive acid, Pepcid usage has been higher in the prior 6 months.