diff --git a/ez-couch.cabal b/ez-couch.cabal
--- a/ez-couch.cabal
+++ b/ez-couch.cabal
@@ -1,5 +1,5 @@
 name:               ez-couch
-version:            0.4.0
+version:            0.4.1
 cabal-version:      >=1.8
 build-type:         Simple
 license:            MIT
diff --git a/src/EZCouch.hs b/src/EZCouch.hs
--- a/src/EZCouch.hs
+++ b/src/EZCouch.hs
@@ -41,6 +41,7 @@
   isolationEntity,
   -- * Types
   Persisted(..),
+  persistedIdHashPart,
 
   -- * Helpers
   tryOperation,
diff --git a/src/EZCouch/Action.hs b/src/EZCouch/Action.hs
--- a/src/EZCouch/Action.hs
+++ b/src/EZCouch/Action.hs
@@ -89,6 +89,7 @@
     handleHttpException e = case e of
       FailedConnectionException host port -> throwIO $ ConnectionException $ 
         "FailedConnectionException: " ++ pack host ++ " " ++ show port
+      ResponseTimeout -> throwIO $ ConnectionException $ "ResponseTimeout"
       otherwise -> throwIO e
     handleIOException e = throwIO $ ConnectionException $ 
       "IOError: " ++ pack (ioeGetErrorString e)
diff --git a/src/EZCouch/Entity.hs b/src/EZCouch/Entity.hs
--- a/src/EZCouch/Entity.hs
+++ b/src/EZCouch/Entity.hs
@@ -10,18 +10,18 @@
 class (ToJSON a, FromJSON a) => Entity a where
   entityType :: a -> Text
 
-  default entityType :: (Generic a, GDoc (Rep a)) => a -> Text
-  entityType = gDocType . from
+  default entityType :: (Generic a, GEntity (Rep a)) => a -> Text
+  entityType = gEntityType . from
 
-class GDoc f where 
-  gDocType :: f a -> Text
+class GEntity f where 
+  gEntityType :: f a -> Text
 
-instance (GDoc a) => GDoc (M1 i c a) where
-  gDocType = gDocType . unM1
+instance (GEntity a) => GEntity (M1 i c a) where
+  gEntityType = gEntityType . unM1
 
-instance (Constructor c) => GDoc (C1 c a) where
-  gDocType = const . pack $ conName (undefined :: t c a p)
+instance (Constructor c) => GEntity (C1 c a) where
+  gEntityType = const . pack $ conName (undefined :: t c a p)
 
-instance (GDoc a, GDoc b) => GDoc (a :+: b) where
-  gDocType (L1 x) = gDocType x
-  gDocType (R1 x) = gDocType x
+instance (GEntity a, GEntity b) => GEntity (a :+: b) where
+  gEntityType (L1 x) = gEntityType x
+  gEntityType (R1 x) = gEntityType x
diff --git a/src/EZCouch/EntityIsolation.hs b/src/EZCouch/EntityIsolation.hs
--- a/src/EZCouch/EntityIsolation.hs
+++ b/src/EZCouch/EntityIsolation.hs
@@ -56,11 +56,15 @@
   -> m ([Maybe (Isolation e)])
 isolateEntities timeout entities = do
   till <- Time.addUTCTime (fromIntegral timeout) <$> readTime
-  results <- createIdentifiedEntities $
-    map (entityIsolationId &&& entityIsolationModel till) entities
-  forM (List.zip entities results) $ \r -> case r of
-    (entity, Right isolation) -> return $ Just $ 
-      Isolation (persistedIdRev isolation) (persistedIdentified entity)
+  results <- createIdentifiedEntities
+    $ map (entityIsolationId &&& entityIsolationModel till) entities
+  results <- return 
+    $ List.zipWith (\e r -> (,) <$> pure e <*> r) entities results
+  deleteEntities $ map fst $ rights results
+  forM results $ \r -> case r of
+    Right (entity, isolation) -> do
+      return $ Just
+        $ Isolation (persistedIdRev isolation) (persistedIdentified entity)
     _ -> return Nothing
 
 entityIsolationModel :: (Entity e) 
@@ -107,6 +111,5 @@
 deleteIsolations :: (MonadAction m, Entity e)
   => [Isolation e]
   -> m ()
-deleteIsolations isolations = 
-  deleteEntitiesByIdRevs $ map isolationIdRev isolations
+deleteIsolations = deleteEntitiesByIdRevs . map isolationIdRev
 
diff --git a/src/EZCouch/Types.hs b/src/EZCouch/Types.hs
--- a/src/EZCouch/Types.hs
+++ b/src/EZCouch/Types.hs
@@ -7,6 +7,7 @@
 import ClassyPrelude 
 import Data.Aeson
 import GHC.Generics
+import EZCouch.Entity
 
 -- | A wrapper for entity values which preserves the information required for
 -- identifying the appropriate documents in the db.
@@ -20,6 +21,11 @@
 
 persistedIdentified :: Persisted a -> Identified a
 persistedIdentified (Persisted id _ value) = (id, value)
+
+persistedIdHashPart :: Entity a => Persisted a -> Text
+persistedIdHashPart (Persisted id _ value) = 
+  fromMaybe undefined $ stripPrefix (entityType value ++ "-") id
+
 
 type Identified a = (Text, a)
 identifiedId (id, _) = id