In addition, there's connecting service from Canada, Europe, South America and the Far East. Commuter service between San Juan, St. Croix and St. Thomas is also available. Commuter airlines can transport you between islands in as little as 17 minutes.n addition, there's connecting service from Canada, Europe, South America and the Far East. Commuter service between San Juan, St. Croix and St. Thomas is also available. Commuter airlines can transport you between islands in as little as 17 minutes.
A rough estimate is that it takes about 14 hours for blood to be broken down within the intestinal lumen; therefore if transit time is less than 14 hours the patient will have hematochezia, and if greater than 14 hours the patient will exhibit melena.
A black stool usually means that the blood is coming from the upper part of the GI tract. At least 6 Tablespoons (or 200 milliliters) of blood must have been lost in order to cause passage of melena. Maroon-colored stools or bright red blood usually suggest that the blood is coming from large bowel or rectum.