This interaction is not true for other acid blockers. Even for tagamet, the increase in levels is so small that it is clinically insignificant. In any case, you should not be drinking and driving at the same time, whether or not you are taking acid blockers. In general, constipation leads to fewer stools that may be hard. Sometimes, the stools are so backed up in the colon, that a part of the hardened stool blocking the passage opens up and liquid stool may squirt around this impaction caused by hardened block of stool.
Treatment involves disimpaction.
Less appreciated is the fact that these drugs may cause ulcers in the esophagus, small intestine, colon as well as the rectum and anal canal. The ulceration by these drugs in the intestine, colon, rectum or anal canal followed by healing of the ulcers may lead to strictures or narrowing of the diameter of the lumen of the gut. On occasions, this narrowing can become significant enough to impede the movement of bowel contents downstream and require some type of therapeutic intervention. Lactose intolerance is a relative deficiency of the enzyme lactase which digests lactose present in dairy products. A cup of milk a day can be tolerated by most people.